I've previously asked the question of which is faster in real world transfer speeds between usb 3.0 and esata. There is very little real world evidence I can find anywhere so I am going to share some of my real world transfer speeds for you to determine which is right for you.
Asus Sabertooth 55i Mobo
6 gb Corsair Dominator Ram
2x Caviar Black 640 gb internal drives 7200rpm
2 TB Samsung F4 5400 rpm
I also have a Thermaltake BlacX ST0005U External Hard Drive SATA Enclosure Docking Station 2.5” & 3.5” USB 2.0 & eSATA and a VANTEC NST-D400S3 Plastic 2.5" & 3.5" White USB 3.0 Hard Drive Dock.
I tested the 2 TB Samsung F4 in the thermaltake esata dock and the vantec dual bay usb 3.0 dock.
Here are my HD Tunes: (first one is vantec and second is thermaltake esata)
HD Tune: Jmicron Corp. Benchmark 2 TB Samsung F4
Transfer Rate Minimum : 56.6 MB/sec
Transfer Rate Maximum : 137.8 MB/sec
Transfer Rate Average : 107.0 MB/sec
Access Time : 14.0 ms
Burst Rate : 94.4 MB/sec
CPU Usage : -1.0%
HD Tune: SAMSUNG HD204UI Benchmark
Transfer Rate Minimum : 58.7 MB/sec
Transfer Rate Maximum : 66.1 MB/sec
Transfer Rate Average : 62.1 MB/sec
Access Time : 13.8 ms
Burst Rate : 63.3 MB/sec
CPU Usage : -1.0%
I transfered 7.59 gb of data/small media files from caviar black 640 gb to the Samsung F4 and had 79 mb/sec with USB 3.0 and 54 mb/sec esata.
I will post more results when I have time to test, but I do believe USB 3.0 is faster by a bit and probably was worth the 80 dollars to buy the dual bay dock and pci express card with usb 3.0.
Should esata or usb 3.0 be faster than what I am getting? Please share with me what results you've personally seen and not technically it should be this fast but never really gets up to that speed.
I haven't done specific benchmarks but my feeling is that eSATA and USB 3.0 are pretty comparable. I tend to prefer USB 3.0 because machines with USB ports are more common that machines with eSATA ports. If your own machine dies and you really need to pull something off one of your external drives it's easy to find a desktop or laptop system with USB ports to plug the drive into. It'll also work just fine (albeit slower) even if you can only find a machine USB 2.0 ports.
Just spent about 20 min trying to find the artical which dealt with this. Could not locate, should have bookmarked it. But the gist of it was that while USB3 should beat esata it did not. (transfer where using external HDDs and SSDs to Internal drives). Also I think there was an artical in MaxiumPC recently - winner Performance - esata - Versitilty, winner USB3 (Goes with what sminlal stated.
On the performance issue, speed is only one part of the equation (yes a major part). It seems that esata is closer to native transmission of data to sata.
I also have the Asus U3S6 card installed, But do not have a USB3 encloser for my external HDDs/SSDs to test xfer rates.
In my experience so far with the only usb 3.0 device (vantec dual dock usb 3.0), I've gotten faster speeds on average than with esata dock or externals. I would recommend usb 3.0 over esata since usb is backwards compatible as well.