SATA heads for 6Gbps, mysteries explained

One bit of news that came out of IDF last week was word from the SATA-IO—the standards body that governs the Serial ATA specification—that it has completed work on a physical layer tweak to allow 6Gbps transfer rates, double that of current SATA devices. The organization decided to go ahead with the release of the 6Gbps physical spec now, while work continues on the full SATA 3.0 spec, which is due for completion before the end of the year. To better understand the upcoming changes to Serial ATA, we spoke with Amber Huffman, Principal Engineer in the Storage Technologies Group at Intel. Huffman is responsible for many storage technology initiatives at Intel, including both SATA and AHCI.

Huffman told us SATA 6Gbps devices and hosts should be backward compatible with devices and hosts based on older SATA revisions, as should current SATA cables. However, the SATA-IO "recommends utilizing quality components to ensure data integrity and robust operation at the fast 6Gbps transfer rate," and Huffman said there may be some tweaks to SATA connectors for 6Gbps. Although achieving 6Gbps transfer rates may require slightly more power use during transfers, Huffman expected that effect to be offset by quicker completion of transfers, placing SATA 6Gbps on roughly equal footing with SATA 3Gbps in terms of power consumption.

Part of the impetus for the move to 6Gbps SATA, Huffman said, is the advent of SSDs capable of saturating a 3Gbps interface, and she predicted SSDs would be the first devices to make use of the new spec. Another impetus for SATA’s move to 6Gbps is the fact that Serial Attached SCSI, or SAS, has already made the move to 6Gbps, and the interoperability between the two standards has pushed SATA. Samples of the first SATA 6Gbps devices are expected early next year, with end products coming in the second half of ’09.

In addition to announcing the 6Gbps physical spec, SATA will be getting a new logo program, as well. The SATA-IO has certified SATA devices for compliance and interoperability for some time now, but it hasn’t had a logo for it. Now, you may have one more thing to peel off of the wrist wrest when you buy a laptop. Certified devices can bear the new "SATA certified" logo.

The SATA-IO is cooking up several new features that may wind up in the final SATA 3.0 spec, including an enhancement to Native Command Queuing intended for streaming data: an abort command. For instance, if the data requested via a read command has become irrelevant during the wait for that request to be fulfilled, the host can send a command to abort the still-outstanding read request. Another much-needed feature is the delivery of power over eSATA, and Huffman told us the main body of work for defining that spec is going on now.

Since we had her cornered, we took the opportunity to quiz Huffman about a few other matters. One of those was the interaction of Native Command Queuing and SSDs. We’re familiar with NCQ as a means of dealing with the seek and rotational latency inherent in mechanical hard drives, but wondered what need there was for NCQ with SSDs. (Intel’s just-announced SSDs have NCQ listed prominently among their specifications.) She said that in the case of SSDs, NCQ has the primary benefit of hiding latency in the host system. If you look at a bus trace, said Huffman, there’s quite a bit of time between the completion of a command and the issuance of another one. Queuing up commands can keep the SSD more fully occupied.

Satisfied with this answer, we moved on to the enduring mystery that is AHCI support. Even at this late date, several years since AHCI first came on the scene, common chipsets from ATI/AMD and Via still don’t support AHCI properly, a fact we’ve pointed out tirelessly. The chipset makers have had few good answers, alway promising a fix in the next driver or chip revision and never—to date—delivering. We’ve found that the best solution to these problems usually is to disable AHCI entirely, which means one loses ACHI’s primary benefits, including SATA hot-plugging, NCQ, and some power-management capabilities.

Huffman was careful not to reveal whatever she might have known about the source of problems for AMD and Via, but she did share some insights about how AHCI compliance is handled. AHCI, or the Advanced Host Controller Interface, is governed by a different group than SATA proper. That group does not collect fees from its members or charge royalties for the use of its creations. As a result, it has no money to conduct an interoperability testing program and doesn’t certify AHCI implementations. The thinking here, she explained, is that the participants ought to be sufficiently capable of doing the legwork for themselves.

Ah. Would that it were so.

Comments closed
    • IntelMole
    • 11 years ago

    /[

    • MadManOriginal
    • 11 years ago

    I don’t know why people complain quite so much about SATA connectors. You have to be pretty ham-fisted to break them and as for being ‘secure,’ once plugged in and inside a case how are they falling out?

      • UberGerbil
      • 11 years ago

      Getting carted to lan parties?

        • MadManOriginal
        • 11 years ago

        I take it that’s a guess since you’ve got a question mark after it. I’d like to know specifically from people to which it has happened exacltly how they’ve had cables spontaneously fall out.

      • Krogoth
      • 11 years ago

      The first generation of SATA cabling and controller connectors were the ones that had the connection problems.

      It is practically a non-issue for current batch of cabling and controller connectors. You also have to treat the cabling itself a little more gently, since they are not like the obnoxious ribbons of the past.

        • MadManOriginal
        • 11 years ago

        Maybe I missed the first generation but I have had SATA drives for a while now and never had the problem, I’m just not a ham-fisted oaf when I work on my PC.

          • Krogoth
          • 11 years ago

          I had work with some first generation connectors and cabling (AXP, P4 Northwood era). Their connection was tedious at best and the connectors were rather fragile to the slightest stress.

          At one point, I had enough of them and replaced the cabling with newer stuff. It was a world of difference. The cabling had some balls and connectors *gasp* cling on to the female end like. Well, I should stop.

      • p645n
      • 11 years ago

      I can’t for the life of me figure out why when sitting down in front of a blank paper the SATA guys did not design a better\easier to use connector. There really is no excuse!

    • pogsnet
    • 11 years ago
      • UberGerbil
      • 11 years ago

      SATA III is not available, just the speed bump.

      Standards already exist for vastly higher LAN speeds. You just have to pay for the equipment.

        • d2brothe
        • 11 years ago

        Also, with regards to the vastly higher lan speeds…there is little point when they are exceeding your harddrive throughput, and in the case of very high speeds, approaching that of your memory bandwidth.

      • moritzgedig
      • 11 years ago

      What do you mean by “LAN”?
      There are many kinds of “LAN”s. Do you mean 10Gb/s Ethernet over copper? your posting makes no sense.
      Gigabit Ethernet should still be sufficient for home-use.

    • herothezero
    • 11 years ago

    q[

      • bdwilcox
      • 11 years ago

      I think it’s totally fetch.

        • SnowboardingTobi
        • 11 years ago

        hahahahaha

      • UberGerbil
      • 11 years ago

      Yeah, only lamestains and cob nobblers use it these days

    • Forge
    • 11 years ago

    Has anyone else noticed the image used and grokked the significance?

    Damage, got a date for that review?

      • Forge
      • 11 years ago

      Ah crap, that was just Bonetrail2 from an unfamiliar angle. Foiled again!

      • Thresher
      • 11 years ago

      You should be banned for gratuitous use of the non-word “grok”.

      I don’t know why, but I hate that term so much. It’s a word that has no reason to exist when there were perfectly acceptable words with the same meaning well before the term was made up.

        • eitje
        • 11 years ago
        • Forge
        • 11 years ago

        Well, I’m glad you’re not in the position to ban anyone.

        Do you have any other points of English usage you’d care to wax dictatorial on, or can we get back to discussing SATA? Was it boring you?

    • UberGerbil
    • 11 years ago

    Having the name “Huffman” and a job involving data storage/transmission and encoding is amusingly appropriate. What’s the term for people who have names that match their jobs?

    • Ragnar Dan
    • 11 years ago

    The first sentence of the second paragraph is written awkwardly. The ordering of words implies that you are claiming that older SATA cables will be compatible with older SATA devices and hosts just as the newer devices and hosts will be. One has to read on to find out from context what you meant to say.

    • Voldenuit
    • 11 years ago

    I still can’t get AHCI working properly with my install of XP x64 on a G35 mobo w/ ICH9R southbridge.

    I can enable NCQ, but the drives still don’t show up as removable device. Using the latest intel matrix storage manager, which is supposed to fix this problem, but still no dice.

      • UberGerbil
      • 11 years ago

      You /[

        • wingless
        • 11 years ago

        I hot swap drives every now and then. I like AHCI and this gerbil does too apparently. It comes in handy when you have a lot of drives with useful data lying around. I might buy a Drobo to help out when I build a Phenom SB750 enabled system that doesn’t have AHCI though.

    • Forge
    • 11 years ago

    AHCI is a Good Thing, and I think the various mobo makers *will* adopt it, but the problem right now is an OS one. The majority of users are running XP and are happy with it, but AHCI complicates OS installs. For folks like you and me who install their own OS, this makes AHCI as much of a drawback as a feature.

    Once Vista gets majority market share (too bad, but it is inevitable), AHCI will take off. Vista, OSX, and Linux all support AHCI natively, with no F6 floppies. For now, there’s actually an advantage to not supporting AHCI for AMD. Nvidia is slowly getting with it and Intel has for some time, that really only leaves AMD out. Via doesn’t matter and hasn’t for some time.

      • ColdMist
      • 11 years ago

      I put together a new x38 system, went to the trouble of hooking up a floppy to load the AHCI driver. Then, the mouse was “jumpy” all the time, under load. ie gaming was like a slideshow, just from the USB input devices, or even on the desktop during app loads, etc.

      So, as a debugging step, I disabled AHCI in the BIOS, and it fixed it.

      I then found a new Matrix driver, installed it, tried to turn AHCI back on, and XP blue-screened. Even having had it installed and working once, I can’t re-enable it without doing some .inf and registry hacking.

      Great.

      I have an eSATA 2.5 enclosure and a 5.25 removable drive rack that I have to reboot when I want to use now.

      That just sucks.

      • Veerappan
      • 11 years ago

      /[

    • Corrado
    • 11 years ago

    So when are we going to get drives that hit the 3gbps max we have now? Let alone 6gbps.

      • Shinare
      • 11 years ago

      Soon… Think SSD.

      • Krogoth
      • 11 years ago

      I think what is more humorous is that majority of controllers on the market are either stuck with a 32-bit PCI bus (133MiB/s shared) or a 1x PCIe 1.0 link (250MiB/s dedicated). Neither of them are enough to fully satisfy 3Gbps or 375MiB/s.

        • BobbinThreadbare
        • 11 years ago

        I thought the SATA controller had a direct link with the north bridge.

          • Krogoth
          • 11 years ago

          That depends on the implementation. The southbridge does not have unlimited bandwidth either.

        • UberGerbil
        • 11 years ago

        That’s what PCIe 2.0 is for. What good are new standards if they don’t force you to replace your motherboard every so often?

          • Krogoth
          • 11 years ago

          Touche’, but most users and businesses do not change their platform around as frequently as their own undergarments. 😉

            • UberGerbil
            • 11 years ago

            Those people probably don’t swap in storage devices that exceed 250MBps (or even 133MBps) sustained transfer rates either.

    • herothezero
    • 11 years ago

    Love my Gigabyte motherboards, but I hate the Gigabyte locking SATA cables; I’ve wrecked two drive interfaces because they didn’t unlatch correctly.

      • ChronoReverse
      • 11 years ago

      Next time, squeeze harder and pull lighter. If it’s not coming off, the solution is not to pull harder.

        • danny e.
        • 11 years ago

        meh

    • sigher
    • 11 years ago

    I wonder if people will try to put it on PCI cards, those just don’t seem to want to go.

    • Joel H.
    • 11 years ago

    Get locking latches. Problem solved, and well worth the added bit of money, IMO.

      • Steel
      • 11 years ago

      My recent motherboard came with a SATA cable with locking latches on each end.

    • mackintire
    • 11 years ago

    deleted …………

    • mackintire
    • 11 years ago

    “As much as a PITA that Molex and PATA cables are, at least they didn’t fall off or worse, break if moved.”

    Have you never seen locking SATA cables? All recent Gigabyte boards come with them as did my Asus Maximus I purchased in march.

    • TurtlePerson2
    • 11 years ago

    You spell her name two different ways in the article.

      • Pachyuromys
      • 11 years ago

      Yep, it’s Huffman… and… she’s kind of a babe. Since Scott’s on such good terms with her, maybe he could persuade her to do a cameo on a report sometime. Maybe just a well-manicured nail pointing out some underfunded malfunctioning AHCI control logic.

      That is, if he stops calling her Hoffman.

    • Thresher
    • 11 years ago

    Now if they could just come up with connectors that didn’t shear of easily and stayed connected when attached.

    As much as a PITA that Molex and PATA cables are, at least they didn’t fall off or worse, break if moved.

      • toxent
      • 11 years ago

      I’ve actually fallen in love with the SATA cables Gigabyte bundled with my motherboard. They have these little clips on them that secure the connector.

      Granted, hardly any other companies do this, but at least i know my SATA cables are secure.

      • Krogoth
      • 11 years ago

      My problem with first-generation of SATA was that connectors on the cable were a little flimsy. These days, cabling quality has improve that it is much less of an issue.

      The trick is that you have to treat SATA cabling more gently. They are not nothing like the awful ribbons of PSCSI and PATA.

        • Meadows
        • 11 years ago

        What’s a PSATA?

          • Krogoth
          • 11 years ago

          It is a typo and you needed to make a post about it? XD

            • derFunkenstein
            • 11 years ago

            well if you spoke English…;)

            • Ragnar Dan
            • 11 years ago

            If he spoke English, we wouldn’t all read his writing and think to ourselves, “Is that Ithkul_prime using his brother’s account?”

            • Krogoth
            • 11 years ago

            It is more like people should stop being huge nitpicks over silly typos. To make make matters worse, they do over a informal, front page thread over anonymous medium.

            It seems that some online people just have way too much time on their hands and not enough real-world concerns to be steaming off over silly typos.

            • UberGerbil
            • 11 years ago
            • Krogoth
            • 11 years ago

            That one is a classic, and the comic number shares the same number as the 3rd generation of x86 architecture (first 32-bit x86 chip). XD

          • DrDillyBar
          • 11 years ago

          Parallel SATA, what of it. 😉

      • sigher
      • 11 years ago

      I can’t say I ever had SATA cable/plug issues (so far), and there are already eSATA cables and plugs for extra sturdiness when it counts, namely external use, but still, perhaps they can update the specs a bit to make some requirements on how strong the plugs are and what amount of pull they should be able to take, can’t harm surely.
      And they need to add power pins to eSATA connector specifications any way so they might as well do both eh.

    • Spotpuff
    • 11 years ago

    r[

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