I am using this model: http://www.wdc.com/en/products/prod... I notice when i hook the device up to my tower which is 1.1 speed, everything is fine, no bottleneck, gaming is great. However when i hook up the external HD to my USB 2.0 PCI card, everything is working slow, gaming performance is terrible. Any idea why it creates a bottleneck? People keep saying it has something to do with my computer, even tho they can't figure out what it is, i can't figure out what it is too. All my IRQ's are normal and fix too.

sounds like a driver issue for your USB 2.0 card...check if the manufacture have a beta version you could try??? also remember this: Esquenet - our engineer friend based in Belgium: "A fast usb host can achieve 40 MBytes/sec. The theorical 60 MB/sec cannot be achieved, because of the margin taken between the sof's (125 us), so if a packet cannot take place before the sof, the packet will be rescheduled after the next sof. On top of that, all the USB transactions are handled by software on the PC. For instance, a USB host on a PCI bus will send or receive the data via the PCI bus; the stack will prepare the next data in memory and receive interrupt from the host."

Go to Device Manager to see what the IRQ assignments are. Your add in card is conflicting with some other high bandwidth device. Right click on My Computer> properties> Hardware> Device Manager. Highlight the very top listing for the computer then click View> Resources by connection> Expand the IRQ entry. List what devices are sharing the IRQ in use by the PCI USB card. Moving the add in card to a different slot may correct the conflict. There is a default IRQ assignment for each slot.