I'm looking to buy an "Gigabyte AMD Radeon HD 6990 (GV-R699D5-4GD-B) 4096MB PCIe x16 Gen 2.1 Eyefinity 6 Edition"
and i can't find anywhere to buy from (OUT OF STOCK).
Perhaps I should go and buy the ATI Radeon HD 5970? Would that give me the same (+/-) Mhash/sec?
+
I'm new to builing a computer - DIY and I was wondering if an "ASUS Socket AM3/AMD 890FX/CrossFireX/SATA 3.0 and USB 3.0/A and GbE/ATX Motherboard Crosshair IV Formula" motherboard is compatible for the 6990 graphic card (I don't really understand the differences between PCI-Express 2.1 x16 And PCI--Express 2.0....etc.).
http://www.amazon.com/CrossFireX-Motherboard-Crosshair-IV-Formula/dp/B003G40Z66/ref=sr_1_7?s=pc&ie=UTF8&qid=1308690889&sr=1-7

tell me what you think? If not compatible so please refer me to any other motherboard that you recommand (for x3 6990's graphic cards crossfire).

thanks