I'm going to post this for information only. As far as I know it doesn't apply to this computer. In the PCIe specification there is a little known provision for a PCIe 16x slot with 25W capacity for "servers". I have encountered this in HP SFF desktops. They actually Spec. fast Core2Quads, 32GB memory, and boast 3x GPU support. 2 of them will be PCIe1x, and the other 25W PCIe16x. Just to save a couple bucks on the PSU.