USB 3 in 2008, 10 Times as Fast

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."

Comments

Size?

[toppavak]

I wonder how adding fiber optic links will affect size and power requirements of USB3 devices. Granted, small LED's use minuscule amounts of energy, but wouldn't having to squeeze in power supplies and photodiodes at each end of the cable make it more difficult to squeeze it all into the micro-USB-sized interfaces used on most phones and mp3 players?

Bottleneck?

[mrjb]

Currently I'm getting transfer rates of about 16 megabyte per second on hard drives connected via USB. That's roughly 160 megabit per second, whereas USB 2.0 can transfer up to 480 megabit per second. While I'm all for faster and better, the bottleneck seems to be elsewhere in this case.

Re:Bottleneck?

[hcdejong]

In the controller, likely. I'm getting 30% higher transfer rates with FW400 than with USB 2.0 on the same external disk.

Which doesn't give me high hopes for USB3. High-speed links are all good and well, but if they keep including cheap-ass controllers, what's the point?

Re:Bottleneck?

[Jah-Wren Ryel]

In the controller, likely. I'm getting 30% higher transfer rates with FW400 than with USB 2.0 on the same external disk. It's as least as likely the problem is in the protocol. USB is synchronous - data every packet received must be acknowledged in a return packet before the next data packet can be transmitted. That back and forth for each data packet means a lot of wasted time where the channel is essentially idle. Sometimes using a shorter cable can make a noticeable improvement.

Firewire has both synchronous and asynchronous modes. In async mode, a bunch of packets can be transmitted before any acknowledgment back is required. That's bad if the cables is flakey, since it will result in a lot of retransmits, but bad firewire cables are the exception, not the rule. So async is almost always way more efficient than synch. I'm pretty certain that you are using the async mode for talking to your disk.

Yeah, but..

[theorem4]

Will this make the new cables more expensive?

Re:Yeah, but..

[LiNKz]

Also, if you integrate an element of fiber optics into a cable that routinely wrapped up, stepped on, or just basically abused, wouldn't it fail far easier than a standard cable?

Plug Shape

[Crock23A]

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.

Re:Plug Shape

[Eccles]

Having it be flippable would mean duplicating wires and/or contacts and would make the cables more susceptible to damage and more expensive.

I don't think the idea is to have the cable flippable, but instead to have some indication in the shape of which way around it goes. Firewire connects have a rounded end and a squared off one, for example.

Re:Plug Shape

[Aladrin]

You're right. I forgot the way more complicated solution. Silly me!

Screw bandwidth...

[Balinares]

Give us a standard that actually delivers enough power that you don't need an additional power cord for just about every other device already... :/

Re:Great.

[BosstonesOwn]

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.

Re:Great.

[antime]

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.

Re:Honest Question

[Yvanhoe]

Apple was thinking along these lines when they proposed firewire. I am not a Mac expert, but from what I have seen so far, firewire can be used for networking (does it use ethernet, I am not sure) video transfer, peripherals connection, external drive connections. From the start it was fast enough and designed for all these applications while we still struggle to get USB working everywhere at full speed...