Battle of the Busses - ProSoundNetwork.com

Battle of the Busses

By Craig Anderton. There’s a lot of excitement about SuperSpeed USB 3.0, a full-duplex data transfer protocol. Regarding speed, we’re talking theoretical transfer rates of 10 times that of USB 2.0—4.8 Gigabits per second instead of 480 Megabits per second. (Of course, it takes a while for real-world specs to catch up with theoretical specs, but it’s happening.) And while on the surface that seems like “just another big improvement,” it’s going to be a game-changer for pro audio.
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By Craig Anderton.

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We’ve had RS-232, RS-422, FireWire, USB…with detours along the way for standards like the Apple Desktop bus and PS/2. Busses are what get data from point A to point B, and only two things matter: Speed and acceptance.

Which is why there’s a lot of excitement about SuperSpeed USB 3.0, a full-duplex data transfer protocol. Regarding speed, we’re talking theoretical transfer rates of 10 times that of USB 2.0—4.8 Gigabits per second instead of 480 Megabits per second. (Of course, it takes a while for real-world specs to catch up with theoretical specs, but it’s happening.) And while on the surface that seems like “just another big improvement,” it’s going to be a game-changer for pro audio.

First of all, you’ll be able to take full advantage of hard-drive speeds, which have saturated USB 2.0’s bandwidth. Copy a bunch of files to an internal eSATA drive and then do the same thing with a USB 2.0 drive; you’ll definitely notice the difference. This isn’t just about saving time when backing up, but also, recording multitrack projects to external hard drives—if you’re into laptop-based portable recording, with a USB 3.0 interface, you can ignore the slower internal drive, and go right to a nice, big, fast external drive. External RAID storage devices will be able to take advantage of 3.0 as well. The cost difference compared to USB 2.0 drives is minimal (for example, you can get a 2 Terabyte Iomega eGo desktop hard drive for a little over $200).

What’s more, USB 3.0 delivers about 50 percent more power to USB peripherals than 2.0—so you may not need those extra AC adapters after all for peripherals that demand more current than 2.0 can provide, or Y-cable hacks for bus-powered hard drives that don’t run reliably.

Second, changes with solid-state drives are on the horizon, too. Flash memory technology itself is the bottleneck with USB but even so, current high-end flash technology is bumping up against 2.0’s limitations, and 3.0 will give flash memory some serious headroom (incidentally, Intel is now shipping its 25nm NAND flash chips, so expect capacity and speed to continue improving). Can you imagine a working environment where the sound of spinning hard drives is gone forever? That certainly appeals to me.

And of course, there’s the matter of audio interfaces. Just as 2.0 interfaces represented a huge leap over 1.0/1.1 models, USB 3.0 audio interfaces will allow more channels, at higher resolutions (both sampling rate and bit resolution). USB 3.0 also means that video devices can now connect to computers via USB.

Backwards compatibility is not a major issue. A USB 2.0 device can plug into 3.0, and some 3.0 connectors (but not all) can plug into 2.0 connectors, with devices running at 2.0 speeds. The only other major difference is that the maximum recommended cable length for 3.0 is typically 10 feet instead of 15. A bigger problem for right now is that few real world motherboards have USB 3.0, so you’re going to need a 3.0 controller card, or for your laptop, a 3.0 ExpressCard.

So what does all this mean for IEEE 1394 (FireWire)? It’s hard to say. Both FireWire 400 and 800 have been eclipsed by USB 2.0, but some would say the situation is analogous to Betamax and VHS videotapes, where the technically inferior solution “won.” FireWire can deliver greater throughput, is already inherently full-duplex, comes much closer to delivering maximum theoretical performance than USB, delivers sustained transfers about twice as fast as USB 2.0, and demands less from the CPU because it offloads housekeeping to hardware. What’s more, the new FireWire S3200 standard is waiting in the wings; although acceptance has been slow, the fact that it uses the same cable and connectors as FireWire 800 at least prevents one roadblock to adoption.

But it certainly seems that USB has the momentum. The areas where FireWire beat USB—like high-performance audio interfaces and video cameras—will have less importance now that USB 3.0 can handle them. More tellingly, S3200 delivers about four times the speed of FireWire 800, or 3.2 Gigabits per second; while S3200’s efficiencies may give performance that’s roughly equivalent to USB 3.0, some people just see the specs, and not the story behind them.

USB 3.0 will also likely impact eSATA, which until now had been the preferred way to connect to external storage devices. However, as it is limited to short cable lengths and can’t deliver power to external peripherals, it is a less elegant solution than properly implemented USB 3.0. eSATA isn’t going to go away any time soon, but then again, neither will USB 2.0. What we’ll likely see is something more like a crossfade, where USB 3.0 continues to gather momentum as other protocols continue to fade.

Craig Anderton is executive editor of EQ magazine, editor in chief of Harmony Central, and an award-winning mastering engineer.