I run a video production company and we use both eSATA and USB 3.0. A few quick thoughts about each:

eSATA:
- we tend to see anything SATA as more stable, at this point, than USB 3.0, because (we assume) the technology has had more time to mature
- it works well for us using RAID 0 on dual external drives where we average 160mbps transfer
- eSATA has pretty solid saturation in the markets so the peripherals are fairly priced
- two drawbacks: first, there are virtually no eSATA flash drives (or none worth purchasing), so you're limited to larger external drives (non-portable) and second, you can't multiply the ports like USB 3.0

USB 3.0
- for us the drivers are a bit on the wonky side of things, sometimes working and sometimes not so much...we have 2 usb 3.0 pci e cards in 2 different desktops, 2 usb 3.0 hubs, a Cavalry USB 3.0 dual hard drive dock and an Iomega ego 1tb USB 3.0 external hard drive...and these things rarely "work" every time they're plugged in
- however, the bandwidth, when it works, seems similar (almost exactly) to eSATA
- the advantage of USB 3.0 is the multiplication of ports and the (hopefully) near term availability of fast flash drives instead of using large eternal plate drives

Hope this helps.

I'll second what drew said. Right now, USB 3 is pretty wonky. Many manufacturers of embedded USB3 are sharing the USB3 bus with other busses, like SATA III. As a result, true 5Gbps performance is only a distant dream. Intel has proclaimed that they won't look at USB3 protocols until 2012. SATA II is here, today.

I have eSATA on my machine and my wife has eSATA on her laptop. It's like "being there". Have not tried USB 3 yet.

my ASRock MB had both eSATA and USB3. I've never been able to get the eSATA to work in either Win XP or Win7-64 bit; maybe just my motherboard problem. However, I do connect regular SATA MB ports (both the 6Gb/S version and 3Gb/S version) to my external RAID array with a cable that has regular SATA connection on one end and eSATA on the other. Unfortunately, the drive randomly disappears when connected to either of these MB connections.

Just yesterday I pulled my ancient 4-port SATA PCI card (with a Sil 3114 chip) from my old P4 Intel MB, put it in the ASRock MB, downloaded Win 7 64-bit drivers, and connected it to the external RAID drive. It has been totally stable! But not especially fast - around 40 MB/S write, 80 MB/S read - probably a consequence of the Sil 3114 chip.

In addition to the on-board USB3 ports, I bought a Siig PCIe>USB3 card. Both are very slow - about 35 MB/S for both read and write. This is in contrast to about 110 MB/S for both read and write on my Hitachi 2TB drive connected to an ASRock SATA port. The slow speed could be due to the cheap USB3 chips in the USB3>SATA Chinese adapters that I use.

However, after I finally coaxed recognition for all 4 backup drives that I always have connected to my computer (through a dual SATA>USB3 cradle from China - ebay) and getting the latest drivers for my ASRock, both the ASRock USB3 port and the Siig card are 100% reliable - the drives are always there when I boot up. Slow, but good enough for backup drives . . .

FWIW...

USB 3.0 is rated up to 5Gbps. In order to achieve this rate, you need to have access to 4 lanes of PCIe. If you have your adapter card plugged into a single lane PCIe, your bottleneck is at the PCIe bus, not the quality of the chips on the adapter card.

true;

My Siig USB3 is plugged into a 1-lane PCIe slot - maybe too slow. I do have a PCIe x16 slot open, and as I recall, one can plug any PCIe card into those slots; true? I might try that. But still, I'm surprised that the speed is only 3x the speed of USB2. Same for the on-board USB3 port.

The Sil 3114 chip goes into a PCI - which also is no speed demon; but that SATA card is about 3 times as fast as the USB3 ports. Is PCI that much faster than PCIe single lane?

I was a very big fan of eSATA... when I had WinXP. Since I upgraded to Win7, I've never been able to get them to work correctly, and I usually end up just using the standard USB option on the eSATA drives, unfortunately. If you google esata windows 7, you'll see it's a common problem. Updated drivers, etc, still a problem. Not a big fan of eSATA anymore.

thanks for the responses... all very useful information! Thinking of going with one of the flex-drive options so that I can hedge my bets and use either the 3.0 or esata adaptor. I have to get a card for the notebook either way and the flex-drive packages are nice because they have all the sets in place.... of course could just save myself the headaches (sounds like I could be in for some) and stick with usb 2.0 and live with the longer render times :)

I doubt you'll see significantly longer render times with USB2 connections for the disk to which you are rendering (previews would be a problem for HD).

But my old sil 3114 chip now has been 100% stable for 3 days - and it's 2x + faster than my USB3. You can still buy cards with this chip on ebay for cheap (or at least cards with a 3112 chip - for 2 ports instead of 4).

Or you could just buy a little adapter bracket for connecting eSATA cables to a SATA port:

http://cgi.ebay.com/2-Internal-SATA-eSATA-External-PCI-Cable-Bracket-/230521126053?pt=LH_DefaultDomain_0&hash=item35ac213ca5

Here's a 3112 chip in a card for your laptop:

http://cgi.ebay.com/NEW-PCMCIA-Cardbus-eSATA-RAID-Sil3112-chip-Vista-/280516468648?pt=LH_DefaultDomain_0&hash=item4150159fa8

Note that they only list drivers for 32-bit versions of Windows, but - in case you are using Win7-64, the drivers that are available on the Sil website should work (I, too, had to download that driver for Win7-64; it works great).

In any case, the ebay price is so cheap - less than $10, with shipping - that I'd definitely try it before resorting to USB.

I will check into that... thanks!