sorry for late reply, been busy.
yes your system is definitely capable of running a usb 3 pci-e card at or near usb 3 speeds, don't know why it doesn't seem to be working for you at usb3 speeds tho, might be a bad cable or might be something driver related.
doubt it's a power supply problem, but can't definitely rule it out even tho i'm 99% positive that's not where the problem is.
only thing i can suggest is to try another usb3 cable, if no luck then completely uninstall all drivers and the device from windows, shut down, take it out of the pc, reboot windows, then shut down again and re-fit it (even tho it is a pci-e x1 card, it can fit and work in the larger pci-e slots so maybe try it in one of those instead when re-fitting to see if you get better speeds, don't see why you should but maybe something else to try.), install the driver directly from the manufacturers site and keep your fingers crossed that solves the problem.
the reason why the intel driver doesn't work is probably because it is the wrong driver for the hardware, or it just doesn't see it as a usb3 device.
have you tried the external hd in your usb2 port and see if it still takes the 2hrs to backup or if it goes back up to 3hrs to do the backup.
if it goes back up to 3hrs in the usb2 port then i'd say usb3 is working fine and that is just the time it takes for whatever reasons to do your backup, and a 1hr saving in time isn't anything to sneeze at anyway.
definitely update your windows os too, who knows that might even fix the speed problem as well as keeping you safer.
this article explains pci express speeds (your motherboard is pci-e 2):- http://www.tested.co...nd-thunderbolt/
Edited by terry1966, 03 October 2014 - 05:59 AM.