Comparing External RAID Housings

@ hawler: USB is NOT a replacement for firewire! There's a reason that ALL pro audio equipment uses Firewire instead of USB. There's a reason that ALL camcorders can stream video only over Firewire and not USB.

It's called "Isochronous transfers". Critical when you're dealing with real-time audio or video. USB doesn't provide that. Also makes bulk data transfer (like backups, for instance) perform more consistently.

USB was never designed for bulk data transfer. That's why it sucks so badly at it. Ever wondered why a 480 Mbit USB2 connection (That's 60 MB/s) can barely achieve between 35 MB/s in real world transfers? That's because the protocol sucks at bulk data transfer. USB was designed for keyboards and mice. To replace low-speed serial ports. Not for high speed bulk data transfer. The USB protocol is inherently deficient in this regard.

Firewire, on the other hand, was designed *specifically* for bulk data transfers. It's obvious when you look at its efficiency at these kinds of tasks. Firewire 400 (that's 50 MB/s) achieves around 42 to 45 MB/s in real world performance. Far FAR more efficient than USB at moving data.

My vote would be for ALL external data storage, audio, and video devices to be firewire only. Make everything else USB.

For those of you asking about firewire, many companies do not like to use firewire because of security issues. Firewire devices communicate through direct memory access. There is no operating system intervention. This is why many companies will have their IT staff remove firewire expansion cards or disable them.

@ njalterio: Companies? IT departments? What kind of company IT department directs their employees to backup the PC's individually using external disks??

Firewire does indeed use DMA. That's another advantage it has over USB, at least in terms of performance. Everyone knows from back in the PATA disk days, that DMA transfers are way faster than non-DMA transfers.

But for professional audio/video, there is only one option and that's Firewire. No such thing as pro a/v products that use USB. They just don't exist. So when you say that "companies disable fw interfaces" I suppose it depends on what sort of company you're talking about. Not a production studio that's for sure!!

There is this program called Hotswap 4.0.1 i think it is. or maybe 4.1.1. I forget. But it's called Hotswap and it allows you to have that add/remove icon for harddrives. It works for cd-roms, ide drives, fixed drives ... it's an amazing program and best of all - it's free!

Again it's hotswap! 4.'something ... http://www.softpedia.com/get/System/OS-Enhancements/HotSwap.shtml it's an amazing tool and it works very well. Solves the problem listed on page 1 about no add/remove icon.

All my applications are installed on the C drive, which is a 500GB $79 WD unit. I buy a second identical drive and hook it up to an extra 18" sata cable and power right at the edge of the pc case chassis.
I use Acronis True Image disk utility to make and exact copy when the system half way reboots. Then I turn off the power and swap disks. A few applications like Photoshop can still detect they have been copied. But besides this its a 5 minute replacement if my HD ever gets corrupted.

Otherwise it takes about 4 LONG days to rebuild the system from scratch.
Five minutes vs four days. Go figure!

Always run the long format and surface scan any new disk to check for bad sectors. Then re-scan it after its been copied and re-booted with. Only then can you state that you backup is worthy.