Catch up on stories from the past week (and beyond) at the Slashdot story archive

 


Forgot your password?
Close
typodupeerror
×
Hardware

Serial ATA, Here and Now 260

Posted by timothy from the smaller-faster-more dept.
Xev writes "We have heard a lot about this new technology; over at HEXUS.net they have a review of a retail drive. The first on the internet, it is interesting to see the performance of the unit as well as the hotswap feature, and other new functions. Is this a solution to cheaper hot swap?"
This discussion has been archived. No new comments can be posted.

Serial ATA, Here and Now More

Serial ATA, Here and Now

Comments Filter:
  • is serial ATA drives that will swap into My portable music player, My PDA and My desktop and laptop computers. Or, to be more exact, I want all of thos different pieces of hardware to HAVE serial ATA functionality... THEN I will be content.

  • Ahem. (Score:5, Insightful)

    by Doktor Memory ( 237313 ) on Tuesday December 31, 2002 @12:23AM (#4986117) Journal
    Is it just me, or were the first several pages of this "article" written by cutting and pasting directly from Seagate's own product description and SATA white papers?

    That they then split the article out over a zillion "pages" to pump up their ad impression numbers is insult on top of injury.

    • Re:Ahem. (Score:5, Interesting)

      by Noehre ( 16438 ) on Tuesday December 31, 2002 @12:55AM (#4986299)
      Obviously you don't read many hardware reviews.

      Welcome to the world of hardware reviews.

      As you'll start to notice, 99% of reviews are spread over billions of pages and generally consist of cut-and-paste descriptions.

      Any actual analysis is so horrible and incomplete as to make the review worthless. Very fiew hardware review sites do an actual good job of doing hardware reviews. Storagereview I view as the best. Too bad they only do hard drives!

      For other stuff, skip right to the Arstechnica hardware forums. Best place there is for mildly biased hardware discussion.

      • Any actual analysis is so horrible and incomplete as to make the review worthless. Very fiew hardware review sites do an actual good job of doing hardware reviews. Storagereview I view as the best. Too bad they only do hard drives!

        Well, what did you expect then? Most of these "hardware review sites" seem to be run by 14-year olds with way too much free time and who drool over the latest-and-greatest because, uh oh, it's the latest-and-greatest. And their mommys are probably proud of them too: "Look daddy, Jimmy is doing all this important uh, community work instead of doing hard drugs and shooting people on the streets. I'm so proud of him!"

  • nice review (Score:5, Funny)

    by Phosphor3k ( 542747 ) on Tuesday December 31, 2002 @12:24AM (#4986129)
    All I get is
    We are having major server problems at the moment. Something is up - we will fix this ;)


    Something is up? Thats a nice way of saying their server is dying under the load of thousands of geeks.
  • We are having major server problems at the moment. Something is up - we will fix this ;)

    Server bashing aside, how does serial ATA compare with SCSI as far as overhead, connection (daisy chain, bus, etc..)?

  • here's the text, server seems to be /. already (Score:5, Informative)

    by Anonymous Coward on Tuesday December 31, 2002 @12:25AM (#4986134)


    Click here to print review

    Review Title: Seagate ST380023AS Hard Drive

    Reviewer: Simon Maltby

    Date of Review: 30th December 2002

    Sample Provided by Seagate
    Introduction to SATA

    Seagate UK kindly have supplied us with one of their new Serial ATA hard drives. We take a look at the new SATA format and attempt to determine what the new format means in real life. Will SATA produce any real improvement in performance?

    Before we begin looking at the physical drive it is worth reading a little about the SATA format. The following extract from Seagate's web site provides us with an insight into the serial ATA standard and more importantly it's expected development path.

    About the Serial ATA (SATA) format

    Most desktop storage systems today use a parallel bus interface referred to as Ultra ATA/100. The parallel ATA interface has been in use on desktop systems as the mainstream internal storage inter-connect, since the 1980\'s (over 15 years!). Today\'s PCs demand higher speeds, more robust data integrity and flexibility for innovative smaller designs. Physically and electrically, the current parallel bus has run into limitations that will prevent this bus from providing higher speeds of data transfers. The move to a new technology is inevitable in the eyes of industry leaders such as Intel, Dell, Seagate, Maxtor and APT.

    These same leaders formed the SerialATA.org and are highly dedicated to bringing this new technology to the forefront of today\'s PCs. Serial ATA is designed to overcome the limitations of parallel ATA while providing scalability for years to come. Setting the goal to be compatible and at cost parity with current parallel ATA drives when in volume, the SerialATA organization is promoting the adoption of Serial ATA in all systems where ATA drives are being used today.

    Serial ATA... the future?

    What is Serial ATA?

    Serial ATA is a \"serial\" architecture as opposed to today\'s \"parallel\" ATA internal disc drive bus. Serial ATA wraps many bits of data into a packet and then at a higher speed (up to 50% higher) than parallel, transfers the packet of data down the wire to or from the host. Today Cyclic Redundancy Checking (CRC) is performed on the data being transmitted back and forth but not on the commands. Serial ATA integrates CRC on the command and data packet level for enhanced bus reliability. Cyclic redundancy code detects all single and double-bit errors and ensures detection of 99.998% of all possible errors. A Serial ATA drive can transfer data at 150MB/sec on the bus to the host system with extremely reliable accuracy and the Serial ATA interface will continue to allow scalability for a very long time.

    Generation 1 Generation 2 Generation 3
    Approximate Data Rate 150mb/sec 300mb/sec 600mb/sec
    Approximate Bus Speed 1.5gb/sec 4gb/sec 6gb/sec
    Approximate Introduction Fall of \'02 Mid \'04 Mid \'07

    Additional Benefits

    In addition to a faster, more reliable bus, Serial ATA improves cabling and connectors for a robust yet simpler integration. Gone are the days of bent pins and clumsy cabling and needless returned hard drives. Serial ATA cables are thinner and longer for improved system airflow and innovative system designs such as small form factor and consumer electronic boxes. Connectors are easier to snap into place without any pins but rather a blind-mate type of connection. Without the wide cables, system integrators can easily route the longer data cables (1 meter) within the system for simplicity or innovative designs.

    Seagate Technology, A Native in Serial ATA Still in its early market entry stage, Serial ATA provides immediate benefits to desktop users. Serial ATA, an innovative new interface, allows continued performance growth, enhanced data reliability, and overall improved system dynamics above and beyond what Parallel can efficiently continue to provide.

    A true \"Native\" Serial ATA solution offers customers the \"Real McCoy\" in Serial ATA technology. By implementing Serial ATA technology, not only on the physical layer of the drive, but also in the ATA controller link and transport layers, Seagate drives can communicate from the drive to the host directly up to the full 150MB/sec speed on the bus. In addition, the native solution incorporates command queuing, which can be a big performance boost in operating systems that can take advantage of that type of function. Some drive manufacturers may not immediately offer these \"native\" Serial ATA features on their 1st generation Serial ATA drives due to the difficulty of this integration.

    The Test Drive I

    The drive it\'s self looks just like any other computer hard disk drive. Consistent with other Seagate barracuda drives this one is very well built, solid and as attractive as a rectangular box of metal and plastic can be. The label clearly identifies the drive and provides setup information.

    Review Model Seagate ST380023AS
    Size 80gb
    Speed 7,200rpm
    Seek Time (Average) 9ms
    Interface Serial ATA

    Here is the description of the drive from Seagate\'s web site...

    Seagate\'s Barracuda ATA V with Serial ATA Interface leverages the mechanics of the industry\'s quietest 7200 rpm desktop drive. The Barracuda ATA V offers 80GB and 120GB capacities with an 8MB cache for mainstream, high performance PCs, and entry-level servers. The product features all FDB motors, superior reliability and the next generation interface - Serial ATA. The SATA Barracuda includes Seagate\'s exclusive 3D Defense System and a one-year limited warranty.

    Features Benefits
    7,200 RPM desktop performance Improves overall PC performance
    350 Gs nonoperating shock Protects drive from shock and vibration
    3D Defense System Industry\'s most comprehensive drive and data protection system
    DiscWizard software World\'s best disc installation software utility
    SoftSonic(TM) FDB motor Quietest acoustics on any desktop drive
    8-Mbyte cache buffer Improved performance
    Serial ATA interface Fastest data transfer rates

    The Test Drive II

    SATA drives can not be connected to your computer with the standard IDE and Molex power connectors as becomes clear when viewing the back of the drive. Two new interfaces are need to use the drive. If you have a motherboard with serial ATA support you will have probably been supplied with an SATA data cable as shown below. However you will also need a Molex to SATA power conversion lead which is not supplied with either the motherboard or hard drive. I can foresee this power lead becoming a source of frustration for many people ordering SATA drives, hopefully when the drives hit the retail market the cable will be supplied with the hard drive.

    Connecting the drive is very easy indeed. The SATA connectors are very well designed and will only fit the correct way round. There are no pins to bend or break as the fittings are more like USB than IDE.

    Currently motherboards with SATA connectors run via the PCI bus. Some have connection via a SATA RAID controller, but our test board used a single SATA connector which is linked to a stand alone SATA controller chip. Once installed and booted the drive was displayed in the Bios taking the place of the primary IDE device. Windows XP located the drive as new hardware and the drive was fully visible. The Seagate drive is fully SMART enabled. This gives access to drive monitoring information including temperature.

    Benchmarks I

    Test Setup

    * DFI NB80-EA Granite Bay motherboard
    * P4 2.66Mhz CPU, 512MB DDR3500 RAM
    * Seagate 80GB SATA150 Hard Disk Drive
    * Maxtor 120GB 8MB ATA133 Cache Hard Drive on IDE
    * Maxtor 60GB 2MB ATA100 Cache Hard Drive
    * 2 Weston Digital 80GB 8MB Cache drives on Promise Raid Controller on Raid0
    * Speedfan utility for SMART monitoring including hard drive temperature

    HD Tech - Read Results Graph

    The HD Tech benchmark is recognised as the most comprehensive hard drive test available. The benchmark evaluates the Hard drives performance across the whole drive regardless of how the drive is partitioned. It is common for performance to drop the further into the drive the test goes. This is due to the sectors at the end of the disk being physically further from the drives starting point.

    Seagate SATA ATA150

    Maxtor ATA133

    The graphs above show two interesting trends. Although the computer was able to read information from the Maxtor drive faster than the Seagate drive, the opposite is true when it comes to writing data. The Seagate drive shows a consistent write speed with a few downward troughs, where as the Maxtor drive shows a few peaks in performance. Secondly although both drives show the expected reduction in read speed the further into the drive the test goes, the Seagate drive shows a slower decline dropping from circa 40k to 25k. The Maxtor drops more steeply from 50k down to 25k.

    The graphs below show the results of all the HD Tech tests carried out during the review. As the benchmark requires unpartitioned drives to test writing speeds only two drives were able to be tested, the Seagate SATA and the Maxtor 120GB 8MB Cache.

    Read speed average results

    Write speed average results

    The Seagate SATA drive did not perform as well as we had hoped in the read tests. Performance was lower than the other 8MB Cache drives whether in a raid configuration or straight forward IDE. The drive is far from being slow, but with the same 8MB Cache and the equivalent of ATA150 transfer speeds we hoped for more. Despite the average scores showing lower the Seagate drive did display better consistency across the drive as a whole and also proved significantly better in the write tests, some 30% better than the Maxtor.

    Benchmarks II

    Sandra Benchmark

    The Sandra benchmark is less reliable than the HD Tech because it tests a partition rather than the whole drive and as we have seen performance changes depending on where on the drive the partition is located. When testing for the review we ensured that all the test drives had the same sized partition and that it was at the start of the physical disk.

    The results show the same story as HD tech, although we are unable to break down the Sandra scores to establish where the Seagate drive falls down.

    General Usage

    Hot Swapping

    An interesting attribute associated with SATA devices is that they should be \'Hot Swappable\', that means that you should be able to move devices around while your operating system is running. On the face of it this would be very useful. Care must be taken when moving hard disks around because while the internal discs are spinning damage can be caused easily. With the SATA drive installed as a non system disk we were able to disconnect the drive with windows XP running. Unlike USB device when removed, windows did not realise that the drive was no longer connected and it remained visible!

    Noise

    Seagate have produced a very well built drive in the ST380023AS. The casing is very solid and the mechanism well balanced. As a result it is most defiantly the quietest hard disk drive I have ever used. If you are looking for an ultra quiet drive then this one should be on your shopping list.

    Reliability

    The test drive was run continually for a week cycling the Sandra benchmark. Although the drive can get quite hot, rising to 45c under very heavy load, it performed without fault. SMART monitoring did not detect any problems during our testing. It should be remembered that a weeks hard testing does not give any real indication of the drives long term reliability, but we can take a great deal of comfort from the fact that the IDE Barracuda drives have proven to be one of the most reliable in the market thus far.

    Price

    Although SATA drives have not hit the retail market place in the UK yet The 80GB Seagate drive is expected to retail for circa £115 including VAT. This puts a small premium on the SATA format.

    Conclusion

    The read performance of the Seagate ST380023AS was not as good as we had hoped for. On the other hand write performance was better than we hoped for. In summary one fact is clear, the SATA interface works differently to the IDE interface and when you consider that this is a first generation SATA drive, linked to a motherboard that has the SATA interface located on the PCI bus, limiting it's potential, the overall performance is very good indeed.

    The benefits of ultra fast data writing would make this drive ideal for write hungry tasks like video rendering or data backup. The Seagate drive itself is very well made and seems to be very robust. Its quiet operation makes it ideal for inclusion in a system where quietness is of benefit.

    Serial ATA is in its infancy. Seagate have produced an excellent hard disk drive at the high quality end of the market place which should be very well received. I for one will be very sorry to have to part with this drive when Seagate ask for it back.

    Pros

    * Very Quiet
    * Robust
    * Very fast write performance
    * Simple SATA data cable connection

    Cons

    * Needs power adapter (Not supplied)
    * Slower read performance than expected
    * SATA comes at a price premium

  • 'bout time (Score:5, Interesting)

    by The Tyro ( 247333 ) on Tuesday December 31, 2002 @12:27AM (#4986157)
    I'm currently building a computer for a good friend of mine, and we had planned on building in a Serial ATA RAID for fault tolerance.

    Yeah, well... We had all the parts weeks ago... all except the !@X&@! serial ATA drives. Nobody had 'em, and nobody could get 'em. We also couldn't find Serial ATA mobile racks to mount the RAID drives... apparently nobody has those either.

    We ended up having to use standard Parallel ATA drives (spare me the "SCSI R0XX0R5!!" flames... this is RAID on the semi-cheap, and it's not a server).

    Ah well, nice to see that Somebody can finally lay their hands on these.

    • Re:'bout time (Score:5, Insightful)

      by AtrN ( 87501 ) on Tuesday December 31, 2002 @03:09AM (#4986663) Homepage
      we had planned on building in a Serial ATA RAID for fault tolerance

      Tolerating failure and using a first release of something don't really go together. Best to wait a while and let others find out what does or doesn't work properly.

  • What is serial ATA? (Score:5, Informative)

    by dagg ( 153577 ) on Tuesday December 31, 2002 @12:29AM (#4986169) Journal
    I didn't have a clue what serial ATA was (I'm not a hardware person), so I did a search and found The Serial ATA Working Group web site [serialata.org]. That site has an interesting picture showing the difference in cables between parallel and serial cables here [serialata.org]. The benefit (with the smaller cables), is that it is easier to maneuver the drives in PC cases. Other benefits of serial ATA are discussed at the web site.

  • Conclusion of article (Score:4, Informative)

    by DynamicBits ( 542509 ) on Tuesday December 31, 2002 @12:32AM (#4986189) Homepage
    Since the site is already /.ed, and people say the first few pages are copied from the manufacturer's site, here is the conclusion:

    Page originally available at: hexus.net [hexus.net]

    Conclusion

    The read performance of the Seagate ST380023AS was not as good as we had hoped for. On the other hand write performance was better than we hoped for. In summary one fact is clear, the SATA interface works differently to the IDE interface and when you consider that this is a first generation SATA drive, linked to a motherboard that has the SATA interface located on the PCI bus, limiting it's potential, the overall performance is very good indeed.

    The benefits of ultra fast data writing would make this drive ideal for write hungry tasks like video rendering or data backup. The Seagate drive itself is very well made and seems to be very robust. Its quiet operation makes it ideal for inclusion in a system where quietness is of benefit.

    Serial ATA is in its infancy. Seagate have produced an excellent hard disk drive at the high quality end of the market place which should be very well received. I for one will be very sorry to have to part with this drive when Seagate ask for it back.

    Pros
    • Very Quiet
    • Robust
    • Very fast write performance
    • Simple SATA data cable connection
    Cons
    • Needs power adapter (Not supplied)
    • Slower read performance than expected
    • SATA comes at a price premium

    • Re:Conclusion of article (Score:5, Funny)

      by p4 ( 632233 ) on Tuesday December 31, 2002 @12:41AM (#4986235)
      Pros:
      Very Quiet
      Sending serially, one bit at a time, is quieter than in parallel? I didn't know bits made so much noise ...
      • Well sure, man, when they travel in packs, they can talk to each other - of COURSE it's gonna be noisier! Sheesh.

  • Simply more convenient (Score:5, Informative)

    by l33t-gu3lph1t3 ( 567059 ) <arch_angel16.hotmail@com> on Tuesday December 31, 2002 @12:49AM (#4986277) Homepage
    SATA will scale better than parallel ATA - PATA is hard to scale given its bus nature. SATA should scale well up to at least 600MBPS theoretical throughput.

    SATA has a smaller footprint than PATA, thus making it more economical to implement in mainboards where PCB space is at a premium. There is also a reduction of signal wires, so again it is more economical to use the drives.

    SATA's smaller cables also allow for more creative formfactors and cabling solutions. PATA had short, wide, and ugly cabling. SATA has longer spec cabling, and its much thinner than PATA's, so cable routing is easier for OEMs.

    Simply put, in its current form SATA isn't really a revolution, it's an evolution of the ATA standard, more out of convenience than anything.
    • The arguments you mark as "economical" also apply to the Fibre Channel vs. SCSI question -- except that Fibre Channel solutions ended up being more expensive. I'm not sure if this is due to various development costs (FC really was intended to be a "revolution"), or simply because some manufacturers decided they could get away with it.

      • Re:Simply more convenient (Score:5, Interesting)

        by FueledByRamen ( 581784 ) <sabretooth@gmail.com> on Tuesday December 31, 2002 @03:28AM (#4986715)
        Have you looked at why Fibre Channel is more expensive? Well, there are a few reasons. FC is designed to be used in HUGE, HUGE datacenter environments. An FC switched fabric can have 16 million devices on it, all speaking SCSI and/or IP. You can run your massive disk array in its own room up to 5km away, thanks to single-mode fiber optics, which are a part of the spec. FC itself isn't too impressive until you look at the bigger picture for it. Another thing it has going for it (like scsi except on a larger scale, unlike Serial ATA unless I'm mistaken) is that in a switched fabric, any device can talk to any other device. For example, my workstation could go over and read a disk that was currently being accessed by 6 other devices from around the datacenter, and it would just put my request in the command queue and respond to it in turn. (Writing is the same way, but you must use a file system designed for multiple writers unless you like FS corruption.)

        Another thing, it's currently faster than SCSI. As far as I remember, 4Gbit FC is out, and 8 (or maybe 6) Gbit is on the way. You don't even need all of your devices to talk that fast (most drives are 1Gbit, maybe 2Gbit), as long as your switch can handle the speed differences, as it should be able to. Even the 4Gbit is faster than Ultra/320 SCSI, and the 6 or 8Gbit will kick the pants off of it.

        Also, unlike SCSI, the cabling requirements are EASY, and the interface cards are inexpensive. I built a JBOD (just a bunch of disks) out of ST39102FC drives (9.1gb 1" 10000rpm Seagate), and you know what I used to cable it together? Cat5. Standard category-5 ethernet cable, at less than 10 cents a foot. Of course, that doesn't include the power cabling, but that's all standardized anyways. Interfacing to an FC drive? Nothing. I grabbed a copy of the drive's tech manual from Seagate's web site, which had all of the pinouts for the FC connector, the SCA40. I whipped up a board in ExpressPCB (because it's easy to order boards from them and the software's free), ordered the mating SCA40 connector from Mouser Electronics, and soldered it all together. It didn't even require any passive components besides a couple of status LEDs (which are optional of course) - just the connectors. Total cost per drive? $10 for the interface card, give or take a dollar, and the cabling is negligable. Buying the connectors and PCBs in bulk will cut down even farther on the cost (mainly because the SCA40 connectors are $6.50 or so in singles). You can have up to 120 drives on a non-switched loop. I'd love to see a SCSI card do that, not to mention the cabling associated! The FC HBA was a surplus HP part which cost me a whole $25 from Fleabay. I soldered my own cable to it where the GBIC module would normally go (thanks, IBM, for the manual on your GBICs!) and popped it in. Finding drivers aside (hpaq's website sucks), works perfectly.

        Of course, one problem with a simple FC loop like what I built is that if you remove a drive, the loop is broken. That problem can easily be solved - Maxim Semiconductor makes a neat little chip that will do port-bypass for you, and the signal for it's already on the SCA connector. Add the chip, the resistor, and the extra PCB space - you've blown a whole $4 more per interface card. Optionally, you could just hook up everything to a FC hub, which handles the bypass automatically. Maxim even sells a chip that basically allows you to build a 4-port FC hub for a few bucks, and they're daisy-chainable to the whole loop capacity of 120 drives.
        • This needs some clarification:

          Fibre Channel drives and SCSI drives cost the same. If they were to cost more they whould have never been accepted into the enterprise (you would see RAID boxes with SCSI inside and FC outside). What make FC more expensive are the switches and management. FC switches contain services such as name, time, and security servers are so complex that even though they've been on the market for about seven years, they still don't interoperate very well. Management costs include complex software and highly skilled administrators.

          You are right about many of the benifits of FC, but speed isn't one of them. The maximum FC speed is currently 2Gb, while 320MB SCSI drives are available. The 640MB SCSI spec. has been finalized, but devices aren't available yet, and 4Gb FC (and 10Gb FC for the backbones) and 3Gb SAS (Serial Attached SCSI) will be available in 2004. That said, line speed doesn't matter all that much because the bandwidth bottlenexk is the head speed (the rate the data is read off the platter). FC and SCSI drives are often the same drive with a different PCB so they have the same head speed, which is currently 50-60MB/s.

          I mentioned SAS before and I thought I'd point out that, like ATA, parallel SCSI is reaching the end of its life. SAS uses similar connectors and cables as SATA and even allows for SATA drives to be plugged into SAS JBODs & RAIDs. Although SAS will only be coming out at 3Gb in 2004, 6Gb SAS won't be far behind.

          As far as your hacked together FC loop, all I have to say is ugh! You can buy T-cards (the industry name for the PCBs you made) that have bypass chips on them and using Cat 5 is just a bad idea. Not to mention your hack to save a few bucks on a GBIC. Ugh! Please don't trust any valuble data to your setup. Oh, and daisy-chaining more than a few hubs together will cause the same problems eithernet has: signal integrity degridation. You need a switch or other device to retime the signal or the device on the far end will have trouble getting bit sync.

          Fibre Channel is for the entrprise. If you want something better than ATA for home / small office use, stick with SCSI. It's just as fast and less likely to cause headaches when you try to get creative when cabling it up.
    • could you possibly have used any more acronyms there? hehehehe good post though ...

      For everyone else reading this ...

      SATA - serial advanced technology attachment

      ATA - advanced technology attachment

      PATA - parallel advanced technology attachment

      MBPS - megabytes per second

      PCB - printed circuit board

      OEM - original equipment manufacturer

      Just in case you aren't Slashdottiness enough to know them already...

  • How good is SATA support in Linux these days? Can I get a SATA card and expect to actually use it soon? Will Linux support Tagged Command Queing on this bus? Will SATA CD-RW drives use more 'native' support than scsi-emulation?

  • Ummm... what's the deal with the special power con (Score:5, Interesting)

    by haggar ( 72771 ) on Tuesday December 31, 2002 @12:55AM (#4986296) Homepage Journal
    Why the new connector? After all, it does plug, ultimately, in a standard ATX power supply. And they even provide a conversion cable ( == less reliable).
    • The new power connector is needed for hot-swap.
      • Thanks.
        But I guess a standard power connector could be provided on the drive, alongside with the new one. So if the drive will be internal, one could use the standard connector, instead of having to use this abomination of a powerconnector adapter. I am a bit paranoid about daisy-chaining power cords.

    • Re:Ummm... what's the deal with the special power (Score:5, Informative)

      by ottffssent ( 18387 ) on Tuesday December 31, 2002 @01:30AM (#4986403)
      New because the old friction-fit molex power connectors suck.

      Actually, it's for hot-swapability. The old molex power connectors would make your drive virtually glued in, and you'd have to jiggle it to get the contacts to fit. The new power connectors are designed for hot-swap operation. They're smaller, easier to slide in and out, and have longer ground wires which ensures the drive is grounded *before* any power is delivered. The same long-short wiring is used in the data cables, where the 3 grounding pins connect before the 4 data pins (two pairs using differential signalling) connect.

      I'm not sure how you figure an adapter is less reliable. Have you *ever* had a molex power connector come apart on you unexpectedly? I count myself lucky if I can get them apart on purpose!

      This early in the migration, there may be issues here and there, but when SATA becomes the standard, there will be connectors for it right on the PSU's cabling, and motherboards will support tons of SATA channels straight to the northbridge rather than ganged onto the PCI bus, and maybe hotswap drives will start to be the norm. Alright, not that last bit, but the first two should happen pretty quickly since SATA is cheaper for the manufacturer, as well as better for the consumer.
      • Have you *ever* had a molex power connector come apart on you unexpectedly? I count myself lucky if I can get them apart on purpose!

        I keep a set of channel locks around for the connectors in one of my systems, and they still usually take 5-10 seconds of pulling to remove. The connectors go in just fine; it's coming out that takes ten minutes and results in pained fingers without tools.
    • because using more conductors on the cable the drive can be powered by the bus cable, it also is needed for hotswap capability.
    • Why the new connector?

      It's cheaper. Notice that the "connector" on the drive is just a routed tab in the PCB, like a PCI/ISA card. The cable itself costs slightly more, but the drive is significantly cheaper because there's no connector at all to install there. The old-style connectors were almost certainly placed by hand before soldering.

      The Tom's HW review sort of implies that serial is somehow inherently faster than parallel, which is BS. Serial is just *cheaper* than parallel. Instead of big honking connectors and bulky ribbon cables, you have a nice thin cable. Data rates aren't a bottleneck with parallel IDE, and if you used the same differential signalling with a parallel interface, you could get n times the bandwidth vs serial, where n == number of pairs.
      • Ummm, no as we are finding out at high speed parallel just doesn't work over any sizeable distance (the fastest parallel conduits are the memory buses on the motherboard and they have to be kept VERY short). Crosstalk interference (helped but not eliminated by differential signaling), timing mistmatches etc are all problems, not to mention that the more conductors the more chance of random interference/breaks. Also the controll logic is cheaper up to a point (if your needed speed for matched performance is at the top of what current silicon can do then you probably are not going to save anything, see Rambus at launch)

  • Don't get too excited about the speed (Score:3, Informative)

    by Nickodemus ( 529872 ) on Tuesday December 31, 2002 @01:59AM (#4986493)
    SATA starts at about 150MB/sec in the first generation, but don't forget that your standard 32bit 33mhz PCI slot can only do about 133 MB per second. New bus technology will need to be implemented before real performance will be seen from these drives.
    • Can't mobo manufacturers use alternative bus options like HyperTransport and MuTIOL (SiS chipsets) to surpass the 133MHz 32-bit 33MHz PCI limit? Or must it all go through the PCI bus at some point? Sorry if that's a stupid question.

    • Re:Don't get too excited about the speed (Score:5, Interesting)

      by Zathrus ( 232140 ) on Tuesday December 31, 2002 @09:44AM (#4987602) Homepage
      *beats head against wall*

      Who gives a crap about the PCI bus speed, or the theoretical maximum throughput of the ATA bus? The drives can't generate more than ~50 MB/s sustained transfer rate anyway. Yup, that's right! ATA-66 is fast enough for every PATA and SATA drive on the market today.

      Oh, sure, you'll spike the transfer rate when reading from cache. I've done the numbers before, and it's something like a 0.1 millisecond difference between ATA-66 and ATA-133, since the largest cache is a mere 8 MB.

      You are correct about SATA being faster than PCI, but it just doesn't matter. Nor do the future possibilities of SATA-300 or -600. The hardware just isn't fast enough.

      And just to cover all the bases, once SATA is integrated into the south bridge chipset it won't be reliant on PCI. In the case of nVidia chipsets (and any Athlon64/Opteron chipset) it would then go over HyperTransport, which is 800 MB/s. I'm not sure what the backplane speed on Intel chips is, but I believe it's faster than PCI.

  • One little note on the hot swap (Score:3, Informative)

    by Arethan ( 223197 ) on Tuesday December 31, 2002 @01:59AM (#4986496) Journal
    I don't think these geniuses performed the hot swap correctly.

    Windows should absolutely NOT report the drive with a letter after you've properly taken out the drive. This is because you are supposed to UMOUNT the fcsking drive before you do it! (There is a windows equivalent to a umount in the drive manager.) This is sort of important considering that any good OS will cache reads and write to physical disks to improve I/O speeds. Pulling a live drive out of a system is likely to create unusable filesystems on that drive.

    BTW: If done correctly, you can easily remove drives from parallel ATA controllers already. In fact, you can buy caddies and mounts for hot swapping ATA/100 drives from a bunch of vendors on pricewatch.

    Oh well, at least they thought they were helping. lmao!
    • While you can buy caddies and make your IDE removeable, it is nor a true hot swap. You can successfully pull it out and in, and it will probably work, but this is not supported in the IDE interface. I have done it, but it is NOT something I would use for anything business related or semi-important. It simply does not work 100% of the time without failures. I am sure you knew this, but I am just informing those who may not know.
      • actually it is up to the drive and the controller whether hot swap works correctly. With any modern ide hdd and a card that supports it hot swap parallel ata should not be a problem. For instance see the 3ware ide raid cards with proper caddies, they work fine and I haven't found one report of a killed drive from these setups, on the other hand the $10 caddies in my pc are certainly NOT hotswap, and neither is the integrated IDE controller on my motherboard.
    • I'd say the "right" way to do it is something along the lines of popping a brace, at which point the drive reports to the OS that the drive is going bye bye so that your filesystem (whatever it is) can stabalize. Once done, the drive pops a second brace, letting you pull the drive out.

      Sure, it sounds error prone, but so does the "tape lacing" mechanism in every VCR. the 3.5" floppy cover and other media protection devices. Hopefully it'll work better than the damn DAT tape ejects that work along a similar principle.

      --
      Evan

  • The next generation of PCI, PCI Express (formerly 3GIO) features scalable bus width. The thinnest version is a single 250 megabyte per second "lane", which sounds like it could potentially replace USB, Firewire and Serial ATA with devices that are directly mapped into processor memory and IO space in a manner that is a bit reminiscent of the origin of IDE drives.

  • Apples and oranges (Score:2, Informative)

    by tuxlove ( 316502 )
    The comparison in the review was basically useless. They compared totally different drive models, in addition to the fact that the interfaces were different. Two significant variables, so there's no way to tell if there's something inherently good/bad about SATA from this review. They should have reviewed two very similar Seagate Barracuda drives, with the interface being the main difference.

    Without even having to review the drive, I'd have to say that when they get the kinks worked out of the firmware, and possibly the host/drive SATA controller(s), these drives will be just as fast in every respect as their older ATA counterparts.

    I know little about SATA, but I would hope that they've fixed the addressing problem inherent in ATA. You should be able to address a large number of devices on a bus, or the benefits of SATA will be limited. SCSI will always be the choice of high-end server class machines until they can fix this problem. Also, the price of the SATA drive doesn't seem all that different from SCSI drives of the same capacity. They need to fix that too.
    • Uh.. My understanding is that SATA is point-to-point only. Well, at least they got rid of that master/slave stuff, and you get the whole bandwidth for a single drive. At least in theory. In practice most SATA chipsets will probably share the bandwidth anyway so the manufacturers can save a few cents. :)
  • I've only read about 3 reviews on SATA so far, and I think it's the next most logical step. However, something that I've noticed missing from comments thus far is that even though they're adding things into the IDE world that SCSI/FC have had for a while (hot-swap, bus-speed).

    Number of heads.

    This is probably the largest reason I don't use IDE in production outside of workstations. SCSI drives normally have 128-256 heads (unless something has drastically changed, in which case I'll no doubt be corrected), where IDE in any flavor has 16. For a home system, it's fine, but for server environments, that's just not gonna fly. Especially where you're constantly accessing numerous files (db, email, 10k virtual site webserver) more heads improve the access rate and help on the ol' wear and tear as well.

    Also, the power couplers kinda freak me out. Tho the molex connectors that we are used to SUCK to remove, they don't come off real easy due to any sort of bumping (ie, sliding the case into the rack or accidentally kicking the tower when sitting down.)

    I do think getting the drive bus the heck off the PCI bus will be a huge benefit down the road, but currently it'll just take traffic off the PCI controller and over to the Northbridge. Might help in ethernet (gigabit) communications not having to share.

    All said and done, I think there is too much hype about SATA. It comes with some good ideas, but things like hot-swap for your average user (floppies are hot-swap, but how many peeps you know STILL pull the bloody floppy out with the light still on..) are not the answer. For myself (and other power-junkies) it'd be kinda cool provided I could purchase a nice backplane or cage for my tower.

    Small gripe on the incredibly shoddy review, though. There's a HUGE difference between 150mb and 150MB. (one is milli-bit, the other megabytes) Normally I won't get onto folks for grammar/spelling, but in this case, it does make some of the graphs, etc. rather confusing.
    • Number of heads.

      This is probably the largest reason I don't use IDE in production outside of workstations. SCSI drives normally have 128-256 heads (unless something has drastically changed, in which case I'll no doubt be corrected), where IDE in any flavor has 16.

      You're totally wrong about the number of heads. The number the BIOS reports is just some fake value for legacy compatibility with 1980s era PC BIOS design. Real harddrives have more like 1 to 9 heads. A huge full size drive (for you youngsters, that's the size of two normal CD-ROM drives on top of each other) might have 16 heads. No hard drive, except maybe some two ton refrigerator sized monster from the 60s, has 256 heads.

      BTW, more heads don't buy you anything, except more heat and noise. Drives can only read from one head at a time.

    • This is probably the largest reason I don't use IDE in production outside of workstations. SCSI drives normally have 128-256 heads (unless something has drastically changed, in which case I'll no doubt be corrected), where IDE in any flavor has 16. For a home system, it's fine, but for server environments, that's just not gonna fly. Especially where you're constantly accessing numerous files (db, email, 10k virtual site webserver) more heads improve the access rate and help on the ol' wear and tear as well.

      Eh?

      The last time I checked a modern drive, heads = platters * 2.

      I've never taken apart a drive and seen more than one head per platter side.

      Care to point me to a drive that does? I'd love to disassemble it.

      Your figure of up to 256 heads per drive on a SCSI drive is very interesting. What size drive has 256 heads? Is it 8 platters with 16 heads per side?

  • Why oh why? (Score:4, Interesting)

    by evilviper ( 135110 ) on Tuesday December 31, 2002 @03:42AM (#4986754) Journal
    Right now, I use IDE on most of my machines. Why? Because most of the time I don't need great disk IO, I don't need more than 2-3 drives, and I can usually live with the lack of reliability that is IDE.

    That said, SCSI is far better, and is doing now, for reasonable prices, what Serial ATA is only claiming it will be able to do eventually, and a lot more in addition. SCSI drives with comparable specs, right now, don't cost much more than IDE drives. If the push to serial increases the prices, suddenly, SCSI will be the bargain interface, as well as the performance interface, which eliminates the entire IDE/ATA market. In addition, SCSI to IDE adapters would give most users backwards compatibility, which would eliminate that from being a benefit to serial ATA as well.

    So, it may soon be time for everyone to make the switch.
    • eventually SATA will cost less as the silicon and connectors will be cheaper to produce and have fewer manufacturing steps as well as aiding in simplified OEM manufacturing steps (remember the hotglue used by E-machines to keep their ide cables attached?)

    • Re:Why oh why? (Score:3, Insightful)

      by Zathrus ( 232140 )
      SCSI drives with comparable specs, right now, don't cost much more than IDE drives

      Uh... right.

      Which is why a 160 GB IDE drive is $205 and a 146 GB SCSI drive is $887. Ok, the SCSI drive is unquestionably faster -- for one thing it's 10k RPM, while the IDE is 7200. And you're right, SCSI command queueing and such make it better in large server situations.

      In virtually every size the SCSI drives cost 2-3x as much. That's not "reasonable prices".

      SATA bumps the price of the drive up by about $20 right now. That's normal with new technology, and once it's mass produced the price difference will disappear. And, actually, as the industry shifts to SATA the PATA drives will become more expensive due to economies of scale (yah, I know, the only difference is in the electronics. That used to be true of SCSI vs IDE as well, and yet the SCSI drives magically cost twice as much still).

      Frankly, I've used both SCSI and ATA drives, and there's no way I'd ever go back to SCSI on a desktop system. The cost/benefit is simply not there. Modern ATA drives are not the godawful beasts of yesteryear, which sucked up massive amounts of CPU and were dog slow. All modern drives use DMA, so CPU usage is no more than 2-3%, pretty much the same as SCSI. The drives are rapidly approaching theoretical speed limits, and the main reason SCSI is faster is because they spin the platters faster. Command-queueing and reordering is nice, but it makes relatively little difference on the desktop. And while the whole master-slave thing does suck, SATA is getting away from that forever.

      Don't get me wrong -- on a serious high end desktop (think medical imaging or CAD/CAM -- your gaming PC does not qualify) or any server I'd recommend SCSI still. And SATA isn't going to change that. But SCSI makes absolutely no sense on the desktop, and hasn't for nearly a decade now.

  • Now we only need one more letter !!! (Score:3, Funny)

    by Zork the Almighty ( 599344 ) on Tuesday December 31, 2002 @04:22AM (#4986886) Journal
    OK quick, we actually have an acronym which is close to being a word here, so everyone try to think of what we can tack onto the END of Serial ATA, preference is given to anything that starts with an "N" !
  • Comment removed based on user account deletion
  • The review on HEXUS.net left a great deal to be desired. HD Tach and SISandra are interesting numbers, but hardly representative of how the drive will react in the "real world." StorageReview has posted a much more comprehensive set of benchmarks on this drive at StorageReview [storagereview.com] Although StorageReview does not yet have the formal review posted, some interesting results do emerge. The SATA Barracuda V drive beats the PATA Barracuda V drive in most benchmarks. For instance, the SR High-End DriveMark 2002 goes from 285 for the PATA to 355 for the SATA. However, since the SATA drive has an 8MB cache vs a 2MB cache on the PATA drive, it's not clear how much the improved results are due to the interface versus the cache.

    Unfortunately, the numbers are not yet available for the File Server DriveMark test, which might give an indication of how much the drive benefits from support for tagged command queueing like SCSI drives have.

    Note that the performance results for the SCSI drives versus the Barracuda V are not a valid indication of the raw capability of the SATA interface. Virtually all of the SCSI drives are 10k and 15k RPM drives, which one would expect to be substantially faster than a 7K RPM drive such as the Barracuda.

    Finally, the explanation on HEXUS.net as to why the drive slows down at the end of the HD Tach test is simply wrong. The review says that "[The slowdown] is due to the sectors at the end of the disk being physically further from the drives starting point." The reality is that the drive slows down at the end of the test because the inner rings are smaller and therefore less data passes under the head for each revolution of the disk.
  • I wrote Seagate sales an email earlier this month asking why the home page of their web site [seagate.com] says, "Available now - The Barracuda ATA V" when it isn't actually possible to purchase one of those drives. They replied that the drives have been shipping to OEMs, but not to the retail channel.

    The email also said that SATA Barracuda V drives were supposed to start shipping to the retail channel in late December, but I haven't seen one show up as "in stock" on CDW or pricewatch.com yet.
  • http://www.lostcircuits.com/advice/sata150/

    Take a look at the article on that website as it actually talks about the more technical issues including why they switched the power connector.

Slashdot Top Deals

He has not acquired a fortune; the fortune has acquired him. -- Bion

Close