Hi all. I've recently built a new PC and I chose the Asrock Z68 Extreme4 Gen3. According to its official specs here: - 2 x PCI Express 3.0 x16 slots (PCIE2/PCIE4: single at x16 or dual at x8/x8 mode) (PCI Express 3.0 with Intel® Ivy Bridge CPU, PCI Express 2.0 with Intel® Sandy Bridge CPU) - 1 x PCI Express 2.0 x16 slot (PCIE5: x4 mode) it features 2 PCI-E 2.0 (I'm using an i5-2500k) that perform at x16 when placing a single graphic card in either slot PCIE2 or PCIE4. When populating both slots (i.e. SLI config), both slots perform at x8. Finally the slot PCIE5 only performs at x4. Well, the above is what I understand Asrock is offering according to specs, which I think are crystal clear. Due to my CPU heat disipator size and planned arrangement I have to connect my graphic card (single, a GTX570) to PCIE4 slot, and expected it to perform at x16 as advertised. I picked this mobo considering this feature and disipator room requirements, among other parameters, of course. To my surprise, PCIE4 is only performing at x8 according to GPU-Z (PCIE2 is empty). When I place my GTX570 in PCIE2 (by removing one of the CPU disipator fans), GPU-Z reports x16 performance (PCIE4 is empty). The mobo User Manual (but not the advertised specs) says that "when using a single graphic card we recommed to use PCIE2 slot for best performance". Not even here they are clearly stating that in order to get x16 performance you MUST use slot PCIE2, or that PCIE4 only performs at x8 (like i.e. they do for PCIE5 in the specs when stating it performs at x4) 1. Can anybody confirm whether on this mobo PCIE4 performs at x8 max, even when PCIE2 is empty? Can PCIE4 be set to perform at x16 in any way? 2. If answers to 1 are both negative, I plan to RMA the mobo for not performing according to specifications, hence my third question. 3. Can anybody list Z68 or P67 motherboard alternatives featuring at least 2 PCI-E 2.0 slot that can perform at x16, no matter the one I choose to connect a single graphic card? Please note: I do NOT mean SLI at x16, but single card at x16. Thank you very much in advance.