Now, theoretically, due to the common controller, the cards should perform identically. Tests were done on each card with Hd Tach to compare the performance of some of the latest USB 3.0 hard disks.
Hd Tach Benchmark Tests
Iomega eGo

Iomega eGo drive test results from three different interface cards
MB/s: longer bars are better, CPU: shorter bars are better
Western Digital My Book

WD MyBook 3.0 drive test results from three different interface cards
MB/s: longer bars are better, CPU: shorter bars are better
LaCie Rugged

LaCie Rugged drive test results from three different interface cards
MB/s: longer bars are better, CPU: shorter bars are better
Overall Average Values

Average results for each USB 3.0 PCI Express card
MB/s: longer bars are better, CPU: shorter bars are better
With such similar performance, the first conclusion is that NEC’s D720200F1 is a very good and consistent controller; repeatedly delivering the performance expected from such devices. Although the benchmark results are almost identical, there are some differences that deserve closer scrutiny.
COMMENTS
Question, + @Paul
@Paul - I saw that too, I'd bet there's a connector in the packaging to connect the FDD to a SATA... maybe...
Does anyone know how well these cards work under Linux?
Compaq...
...as I remember correctly, carried the first usb ports on their system boards. They, of course, didn't work because Windows 95 didn't have proper drivers yet. There was a patch which allowed a few USB devices to be recognized. Then came USB 1.0 and Windows 95 sr2. Software for USB devices (mostly Logitech webcams) became widely accessible. Software faltered and devices crashed numerously. Compatibility? Humbug!
USB 1.1 was more stable and hardware manufacturers used this standard to build their USB chipsets. External hard drives caddies were adapted to the plug and play hierarchy. In came the USB flash-drives (then called thumb-drives. Whatever happened to the name?)
512Kb, 1Mb, 2Mb, 4Mb, 8Mb, 16Mb, 32Mb etc.... etc...
Back then it was compatibility. Now it is speed. Me?
I care about data. I don't care at what speed it is transferred. As long as I can use it when I want to.
Video, audio or data, I want it to be Plug and Play. I struggled with drivers, compatibility and, heck, even not knowing if my data was still secure after plugging my USB device in an open slot of an unsavory machine , but I want to leave that behind me.
I'd better stop worrying now and look at Cloud. Nice expression to be used here is; silver lining.
Re: Turn up the Power
USB 3.0 contains a set of USB 2.0 pins, but these run at the standard USB 2.0 specs because they're a standalone USB 2.0 bus that runs alongside the separate USB 3.0 connections.
http://www.reghardware.com/2009/05/25/superspeed_usb_3_guide/
Turn up the Power
I'm more worried about this disturbing trend to offer 2 or 3 times the power output on USB3 ports.
The pins on USB3 are the same size as USB2 and that offers 0.5A .
Now USB3 is suppose to offer 0.9A. But with cards and Mobos (see Gigabyte) offering 3 times that, how on earth is 2.7A (13.5W!) going to flow through that same pin? It beggars belief!
Expect USB3 to develop a reputation of smoke, fire and melted plastic.
SATA
"Buffalo actually supplies an adapter to plug into a SATA power cable"
Looks more like a fdd power connection to me ;-)
