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Asus Delivers Speed Boost With USB Attached SCSI Protocol

Posted by timothy on from the for-sufficiently-small-values-of-universal dept.

MojoKid writes "When USB debuted in 1999, it offered maximum throughput of 12Mb/s. Today, USB 3.0 offers 4.8Gb/s. Interestingly, modern USB 3 controllers use the same Bulk-Only Transport (BOT) protocol that first debuted in 1999. Before the advent of USB 3, relying on BOT made sense. Since hard drives were significantly faster than the USB 2 bus itself, the HDD was always going to be waiting on the host controller. USB 3 changed that. With 4.8Gbits/s of throughput (600MB/s), only the highest-end hardware is capable of saturating the bus. That's exposed some of BOT's weaknesses. UASP, or the USB Attached SCSI Protocol, is designed to fix these limitations, and bring USB 3 fully into the 21st century. It does this by implementing queue functions, reducing command latency, and allowing the device to transfer commands and data independently from each other. Asus is the first manufacturer to have implemented UASP in current generation motherboards and the benchmarks show transfer speeds can be improved significantly."

21 of 93 comments (clear)

  1. This will never catch on if... by kungfuj35u5 · · Score: 2

    Asus doesn't inexpensively license the technology to other board oems. Not sure how much of this is software and how much is hardware, but if there is a special USB-SCSI command set that is separate from plain SCSI then they will need to be open and supporting on that front for all OS's as well.

    1. Re:This will never catch on if... by mcbridematt · · Score: 5, Informative

      It isn't proprietary - it is part of the USB3 spec, but hardware that actually supports it appears to have been missing, until now. There has been a Linux driver for a while now, and TFA says Windows 8 will implement it too.

    2. Re:This will never catch on if... by Jeremiah+Cornelius · · Score: 2

      In the protocol arena, I find it funny to discuss adding SCSI moves a technology into "the twenty-first century".. :-)

      Speaking of that, something else strikes me...

      USB debuted in 1999?

      I had USB in Windows 98.

      So 1.0 must have been so slow, that it ran backwards in time!

      --
      "Flyin' in just a sweet place,
      Never been known to fail..."
    3. Re:This will never catch on if... by mister_playboy · · Score: 4, Informative

      USB debuted in 1999?

      I had USB in Windows 98.

      TFS is just plain wrong. From https://en.wikipedia.org/wiki/USB...

      "The original USB 1.0 specification, which was introduced in January 1996, defined data transfer rates of 1.5 Mbit/s "Low Speed" and 12 Mbit/s "Full Speed". The first widely used version of USB was 1.1, which was released in September 1998. The 12 Mbit/s data rate was intended for higher-speed devices such as disk drives, and the lower 1.5 Mbit/s rate for low data rate devices such as joysticks."

      --
      Do what thou wilt shall be the whole of the Law ::: Love is the law, love under will
    4. Re:This will never catch on if... by jbolden · · Score: 2

      Good point. But it appears that USB hardware is cheaper than esata, I don't know if that reflects costs of manufacturer but I'd assume so.

      Also you could have it fall back to the standard.

    5. Re:This will never catch on if... by otuz · · Score: 2, Informative

      No, USB 1.0 headers were present on some motherboards in 1996 or so. Practically no device support, barely anyone knew what it was. USB 1.1 debuted in 1998. iMac was the first machine to get rid of the old peripherial ports in favor of USB 1.1, in 1998. It drove great demand for USB devices. USB 2.0 was early 00's stuff.

    6. Re:This will never catch on if... by UnknowingFool · · Score: 2

      Yeah the problem on the Windows side was drivers and devices. Kinda chicken and egg problem. Manufacturers didn't want to develop drivers and make devices until they knew consumers would buy it. Consumers wouldn't buy devices until they knew there were drivers. USB would be adopted eventually; it was just a matter of time.

      The iMac didn't start USB adoption but it helped speed it along as there was only USB or FireWire. FireWire would be too expensive and overkill for most peripherals. Manufacturers knew that they could make devices for Macs at least. Having devices both PC and Mac compatible at the same time helped lower the barriers. In the long run it would be slightly cheaper as manufacturers didn't have to support 3 or 4 connectors anymore (DIN, de-9, LPT, game port, etc.)

      --
      Well, there's spam egg sausage and spam, that's not got much spam in it.
    7. Re:This will never catch on if... by lindi · · Score: 3, Informative

      You can only use six non-modifier keys at the same time. This is a problem for playing older multiplayer games. See appendix B.1 of the USB HID 1.1 specification.

    8. Re:This will never catch on if... by dotancohen · · Score: 2

      Asus doesn't inexpensively license the technology to other board oems. Not sure how much of this is software and how much is hardware, but if there is a special USB-SCSI command set that is separate from plain SCSI then they will need to be open and supporting on that front for all OS's as well.

      I came to say the same thing. Linux users can no longer buy Asus motherboards (at least not the budget boards) as the new integrated LAN card does not support the legacy Realtek drivers. Even Windows cannot get online with them until one installs the near 1 GiB "driver disk" with all its other unrelated junk. And before you tell me to just install a PCI LAN card, some models (including the one I bought) don't even have PCI slots!

      I didn't mean to rant. But Asus can no longer be trusted as a supplier, so any technology that is Asus-only is DOA.

      --
      It is dangerous to be right when the government is wrong.
  2. I like my drives by Anonymous Coward · · Score: 5, Funny

    like I like my women, FAST, WIDE and SCSI

  3. throughput vs bandwidth by sribe · · Score: 4, Insightful

    When USB debuted in 1999, it offered maximum throughput of 12Mb/s.

    Well, no, it didn't. It was based on 12Mb/s signaling rate, but delivered substantially lower actual throughput. There's a paper on the usb.org website that runs through it all, showing how the relatively large overhead of the protocol affects throughput.

    1. Re:throughput vs bandwidth by tjb · · Score: 2

      You could get 8Mbps on the isochronous channel if you were the only isochronous device on the bus, plus, IIRC, 256Kbps on the bulk channel in both directions and a teensy little bit more on the interrupt channel if you were being creative/dangerous. If there were no isochronous devices on the bus, I think you could get something like 8.5Mbps on the bulk channel.

      Of course, it's been over a decade since I've worked on a USB device, so I could be wrong. Except about the isochronous channel - coming up with a way to shove 8192Kbps of ATM traffic through an 8Mbps USB 1.0 isochronous link required some epic hacking that I will never forget :)

  4. Re:In other words... by arth1 · · Score: 2

    No, Firewire (Apple's implementation of IEEE1394) would allow two external drives to talk directly to each other without going through the host.

    This isn't even like SCSI, as there's no true DMA. It's more akin to NCQ. The benefits are there, if you use it for copying from RAM or SSD to USB. Otherwise, you won't notice much difference.

    I'd much prefer ESATA myself, not the least because it can allow AHCI and TRIM, but also because it won't slow down if you use multiple drives simultaneously.

  5. Does SATA fit into the mix anymore? by jabberw0k · · Score: 3, Interesting

    With UASP sufficient to provide a good disk interface, will new motherboards keep it simple and eliminate the SATA controller and ports? Will new internal hard drives simply have USB connectors?

    According to Electronic Design,

    Using a common command set reduces support and compatibility issues. SATA flash and hard drives support a subset of SCSI, which is why SAS controllers can easily handle SATA and SAS drives. This also makes support of these drives via UASP significantly easier. Likewise, it means standard device drivers for operating systems like Windows and Linux work with all devices.

    So, a kernel could have a single SAS driver that supports all SAS, SATA, and USB block devices. This could be a marvelous convergence.

    1. Re:Does SATA fit into the mix anymore? by silas_moeckel · · Score: 2

      Good disk performances at the expense of high CPU use. USB is the winmodem of storage it will never be the preferred method if your want performance. I expect there will be plenty of SATA to USB3 bridge chips available.

      --
      No sir I dont like it.
    2. Re:Does SATA fit into the mix anymore? by Lord_Naikon · · Score: 3, Interesting

      So, a kernel could have a single SAS driver that supports all SAS, SATA, and USB block devices. This could be a marvelous convergence.

      I know FreeBSD does that, using the CAM (Common Access Method) subsystem. Presumably other OSes do something similar.

  6. Great for audio by dontmakemethink · · Score: 3, Interesting

    This finally resolves the biggest problem for USB interfaces and hard drives for audio. The primary factor for performance in audio has always been access speed (seek time), and not throughput. Audio software has to access dozens of separate audio files in a very timely manner frequently, and the overhead of the USB protocol has always been a wrench in the gears. From what I'm reading, UASP offers the same advantages NCQ (Native Command Queuing) offers in SATA, which allowed for much higher track counts on the same drive rather than spreading files across several drives, which was a pain in the butt. It was only with NCQ in ~2005 that SATA finally caught up with SCSI-2 (ca 1994) in audio performance, provided the drive was 7200rpm or faster. Firewire has some form of queuing system built into the host, so it's always been better than USB for audio, but it is vanishing from laptops and desktop motherboards, even Apple products.

    Now watch how long it takes before audio hardware manufacturers adopt it, and feel our pain. The first Firewire audio interfaces came out about 4 years after Firewire was standard on Mac desktops...

    --

    War as we knew it was obsolete
    Nothing could beat complete denial
    - Emily Haines
  7. SCSI over USB?! by Dasher42 · · Score: 4, Funny

    Just when I'm really, really tired of the acronyms, there's SCSI over USB. What's next, orange juice out of apples? Kia to Tesla conversion kits? Vegan outback steakhouses? Elegant Perl code?!

    1. Re:SCSI over USB?! by red_dragon · · Score: 2

      The seven-layer cake is a lie.

      --
      In Soviet Russia, Jesus asks: "What Would You Do?"
  8. Re:In other words... by TheGratefulNet · · Score: 3, Informative

    esata is just sata with some very very minor phys layer changes. its still sata.

    and sata is identical to sas at the phy layer (controllers often can be used for both with diff firmware). ide, as we once knew it, morphed into sata and sata and scsi are now 'friends' in a way.

    ahci is the 'real' form of sata. old compatible stuff was just that, running ide over over the sata phy layer.

    trim exists whether you run esata or local sata. trim does need ahci (ie, true modern sata) but does not care or know if its internal or external.

    just to clear that up a little..

    --

    --
    "It is now safe to switch off your computer."
  9. Re:USB as RAM? by TheGratefulNet · · Score: 4, Interesting

    search for 'vertical usb flash' and you can find internal tiny usb 'thumbdrives' that mount right on the 10pin (iirc) usb mobo header. inside the case. has been that way since about the start of vista days (1gb was somewhat common as a 'cache' you could use).

    --

    --
    "It is now safe to switch off your computer."