I know that this is an older thread, so apologies for the necro, but I've upgraded the ATC-605-UB11 and may have some insight for future people who find this thread. First, you will need to upgrade the power supply. The factory is a 300 watt PSU, but it's simply not good enough to power mid to high end GPU and the additional accessories you'll need. Second, a low profile/slim version of graphics card will work. Full sizes, not so much. Third, the USB toggle is directly below the PCI-E slot. A GPU will fit, BUT if you want to keep your front USB ports, you will need to work a way to lock in the GPU or it can/will pop out because of the USB cord pushing against it. Finally, there is basically no air flow in the case, so it is highly recommended that you modify the case to add a couple of fans to it OR the GPU will run hot constantly. Cheap workaround for this is to leave case open and find a small cheap USB desktop fan and set it beside the GPU in the open case. Turn on when running games with high GPU demands.