This is a great and inexpensive device to boost your file transfer rates.
Two important things:
1. It doesn't come with a molex splitter as some past reviews state, the product name and description now reflect that change.
2. The newest version, being sold now, *doesn't require* an additional power supply to give full USB3 speeds and power - which is why the molex splitter is no longer included.
This is a very cost effective way to boost the speed of file transfers to and from external drives. A USB 3 capable portable drive I have transfers a 700MB file from it through USB2 at around 35 MB/s. Using USB3 via this card it transferred at a speed of around 100 MB/s. The marketing guff around USB saying 10 times the speed is exactly that: guff, but it performs appreciably faster than version 2 and can save sometimes valuable time.
Microsoft is still behing the curve and doesn't include USB 3 drivers in Windows 7 or via Windows Update (that may change) so you have to install driver software to make the card functional. Interestingly (and uniquely) the mini-CD that came with my card included a driver version NEWER than the one availbale on the internet (at a site the manual gives the link to).
The driver installed flawlessly and without hitch.
For only £9 for this card, which you now only have to plug straight into a PCI express slot to triple or quadruple your speeds (using USB3 devices) it's a no-brainer.
(Thanks to TeckNet for promptly addressing the matter of the splitter and the reviews that mentioned it, the same day I brought it to their attention.)