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USB 3 in 2008, 10 Times as Fast

Posted by CmdrTaco on from the i'll-believe-it-when-it's-on-my-laptop dept.

psychicsword writes "Intel and others plan to release a new version of the ubiquitous Universal Serial Bus technology in the first half of 2008, a revamp the chipmaker said will make data transfer rates more than 10 times as fast by adding fiber-optic links alongside the traditional copper wires." "The current USB 2.0 version has a top data-transfer rate of 480 megabits per second, so a tenfold increase would be 4.8 gigabits per second." This should make USB hard drives easier and faster to use."

12 of 381 comments (clear)

  1. Re:Cable? by YrWrstNtmr · · Score: 5, Informative

    The last line in the article:
    "It will be backward compatible, so current USB 2.0 devices will be able to plug into USB 3.0 ports."

  2. Re:I'm more concerned with latency. by Laebshade · · Score: 5, Interesting

    I can't find the exact article, but you should read this one about the effective USB 2.0 speed. It states that the effective maximum speed is only about 40MB/sec, and that 60MB/sec can't be achieved due to overhead/software limitations; not sure if this is true now.

  3. Plug Shape by Crock23A · · Score: 5, Insightful

    Could be slightly off topic but I had to sound off on this one...

    While I appreciate USB's capability for backwards computability, I would much rather have a plug shaped in such a way that I didn't have to flip it over every time I try to plug it in. I don't know about you guys but this is one of the most annoying aspects of using my computer, and I run Windows!

    This would also be a great time to make a universal "other side" of the cable, rather than having a different plug for every single USB device. I have a mini plug for my camera, a big square one for my printer, a 2.5 mm jack to charge my MP3 player, etc. All these cables make a mess. If all my devices could share one cable, I'd be much happier.

  4. Re:Great. by morgan_greywolf · · Score: 5, Informative

    1.5 seconds if you all of your components were fast enough. The drive won't be. Exactly. There's still the slowdown associated with the mechanical aspects of the hard drive -- spin rate (RPM), average seek time (ms), etc. On top of that, most hard drive controllers are limited by the technology they use. For instance, a SATA hard drive, even plugged into a USB 2 or 3 port, is limited to 150 MB/s -- but, that's burst speed, not sustained transfer rate.
    --
    My blog
  5. Re:I'm more concerned with latency. by Televiper2000 · · Score: 5, Informative

    My experience with USB is that it has lousy thru-put do to the way the drivers manage data on the host side. We did some heuristic timing tests on USB to serial devices and found that most of them actually degraded the thru-put (time send and receive a packet) of an RS232 connection. We found that devices with Silicon labs ICs could get the desired thru-put, but it seemed they would take up an entire USB channel to do so.

    --
    New! Device Legs: These legs will help your poor OEM installed product escape any hamfistedness it may encounter. Ava
  6. Re:I'm more concerned with latency. by schwinn8 · · Score: 5, Interesting

    Exactly... Firewire400 works well for video streaming from a DV cam because it has very little overhead. Even though USB2 supposedly does 480Mbps, it can't do DV because there's too much overhead. Bottom line is, unless USB3 gets rid of the CPU dependency and overhead issues, I won't like it. Sure, with a "ten times" the performance, this won't hinder DV, but that doesn't make it good. I hope they make it systemically-efficient, instead of just ramping clock rates to reach these speeds.

  7. Re:Great. by BosstonesOwn · · Score: 5, Insightful

    http://en.wikipedia.org/wiki/Flash_memory

    No Flash is slow to write , very fast to read. Hence Windows use of it for "ReadyBoost" caching. There is extremely low latency just not enough bandwidth to sustain high levels of I/O.

    On the other hand , by introducing fiber into the link doesn't that take away the greatest part of usb ? being able to just fold up the cable and stuff it in your pocket along with a small hard drive ? I know I use it for restoring machines after catastrophic failures (yeah windows) and some times I don't go right back to my desk with the cable and drive and have to toss it in my pocket. I can't do that with fiber, it would fracture.

    --
    This package Does Not Contain a Winner
  8. Re:Great. by antime · · Score: 5, Insightful

    The quoted speed of USB 3 is probably the bus speed, i.e. it's shared by all devices connected to the same host. So one disk won't saturate the bus, but if you plug in a bunch of them the bandwidth won't seem so incredibly massive anymore. Then you have to consider the bandwidth reserved by isochronous devices etc.

  9. Honest Question by martyb · · Score: 5, Interesting

    I've got a question that has been nagging at me for quite a while and was hoping someone here could phrase an answer in terms a mere mortal could understand.

    Why are there so many serial specifications?

    We've got, off the top of my head, SCSI, USB, Ethernet, FireWire, and SATA to name a few. I do understand there are different protocols (all the way up from the physical to the application layers). Different applications of these technologies permit some optimizations that might not be applicable in other situations. But, at some point, the underlying technology is fast enough

    Still, I can't help but think there should be some common denominator that ALL these communications standards can agree on, and through economies of scale, become universal standard(s). It just seems like people keep re-inventing the wheel with an eye toward THEIR favorite.

    I thought we were getting close when they released gigabit Ethernet over UTP (unshielded twisted pair).

    • can handle distances up to 100 meters
    • fast data rate (1000 Mbps)
    • supports lower data rates (100/10 Mbps)
    • development is underway for 10Gbps, too.

    So, for the sake of argument, why not have all of our serial devices just support gigabit Ethernet? Sure, you'd need a hub or switch in your PC to talk to all of the devices, but you already need something similar for the other protocols (USB hub, SCSI controller, etc.). It's a well-known technology with many implementations and is widely available. I'd willingly pay a few more bucks for each device if I could ditch all of these incompatible formats and just standardize on one SET of ports and cables for hooking things to (and within) my PC. And in those cases where a different connector is desired (e.g. for small form-factor devices like a digital camera), let me just get an adapter cable/plug that I can plug into my Ethernet port.

    Is there any good, technical reason that is keeping us from having truly UNIVERSAL serial communications?

  10. Re:I'm more concerned with latency. by Barny · · Score: 5, Interesting

    Mod parent up, hammer meets nail in their post :)

    Bonus points if you hook a 108mb/s wireless lan adapter via USB and throw some large data files over it, watch your data speeds closely, and monitor system performance even closer.

    Firewire (1394, ilink, DV port, whatever) really was the shit, not only fast, low overheads AND its a peer-2-peer setup, in a pinch you could daisy chain PCs with it for an impromptu 400mb/s lan.

    Why didn't they just hang USB out to dry and get power into the eSATA spec and use that? At least then no extra chips would be needed on a mobo, external HDD would hookup with no loss in performance and we might finally see thumb drives that work natively with ANY os as... drives.

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    ...
    /me sighs
  11. 0.9 TB / 4.8 Gb/s = 1500 seconds by Anonymous Coward · · Score: 5, Informative

    WTF, a chain of "Exactly" and "Indeed", and no one realizing that 1.5 seconds is wrong by a factor of 1000?

  12. Re:Cable? by ddstreet · · Score: 5, Informative

    > like if you plug a usb 1.X device onto a usb 2.0 bus, then everything slows to usb 1.X. IINM...

    This is wrong, if you plug a USB 1.1 device into a USB 2.0 "bus" then it does NOT slow everything down. Specifically there are 2 cases:

    1. You plug a USB 1.1 device directly into your computer (i.e. directly into the "host controller"). In this case, the USB 2.0 host controller (technically a EHCI chip) does NOT talk to your device. Instead, the EHCI chip has one or more USB 1.1 host controller chips (technically either a OHCI or UHCI chip, and called a "companion" chip when inside a EHCI chip) and your USB 1.1 device is connected electrically to that controller. You device is not on the USB 2.0 (EHCI) bus.

    2. You plug a USB 1.1 device into a USB 2.0 hub. In this case, the USB 2.0 hub creates a complete USB 1.1 environment specifically for your device. On the host-facing side of the USB 2.0 hub, all communication continues to take place at USB 2.0 (i.e. 480Mbps) speeds. When the host wants to talk to your USB 1.1 device, it uses what is called "split transactions" to talk to it. Basically (I'm simplifying), this involves sending a "start" packet to the USB 2.0 hub. Then, the USB 2.0 (EHCI) controller goes on to do other things, while the USB 2.0 hub initiates the transfer to your device at USB 1.1 speeds. And data transferred from the USB 1.1 device is stored temporarily in the USB 2.0 hub. Eventually the USB 2.0 (EHCI) host sends a "finish" packet to the USB 2.0 hub. If the USB 1.1 transation finished, the USB 2.0 hub responds successfully (either with the incoming data or a "ack" that the outgoing data was sent) which completes the transation.

    (There is also a combination case of those, where the EHCI chip does not contain a "companion" USB 1.1 chip, but instead contains an internal USB 2.0 partial hub - the "transaction translator" part - that handles talking to USB 1.1 devices. For bus usage purposes, this is effectively the same as using an external USB 2.0 hub, since the USB 1.1 devices do not appear on the USB 2.0 bus.)