I wanted to get an x79 chipset then I keep reading that it only supports intel i7? Thing is the CPU I plann on getting is the i5, does this mean I have to get a z68?
I know that if you plan on going for a multi gpu setup the best mobo to go for is the one that has multiple slots that operate at x16. Is there a board that has three slots for gpus that all operate at x16 all at the same time? So far the only things that I've seen can only support 2 x16 anything more results in a x8 setup.
It depends on 'How many' GPUs you plan on adding, for 2-3WAY then the LGA 1155 platform with either P67 or Z68 chipsets; 3-WAY SLI requires an additional PCIe chipset (NF200). Otherwise, 3-WAY to 4-WAY X79 on LGA 2011 and the SB-E CPU's. The only two platforms that can currently 4-WAY SLI are the older X58/LGA 1366 and current X79/LGA 2011. Currently, the SB-E CPU cost is double to triple that of the LGA 1155 SB. SB = Sandy Bridge 4-core; SB-E = Sandy Bridge Extreme 6-core.
Sometime Q1, mid February, Intel will release the i7-3820 SB-E for ~$300USD which will be 4-core and compatible on X79.
Intel Core i5, i5-2XXX, series will not be supported on the LGA 2011 platform.
Currently an of some period of time to come no GPU fully saturates x8 PCIe 2.x lanes (8 * 500MB/s). When comparing x8 vs x16 there's usually a small bump in performance many folks including myself feel it's in part due to the driver sensing more lanes, but no proof. You can see the same 'bump' even on the same platform.
Hopefully soon Thomas will do an X79 (32-lanes) vs Z68 (16-lanes). Keep in mind there's the CPU factor in X58 vs Z68/P67 vs X79.
Further, here's an interesting PCIe 2.x vs 3.x bench proving what folks like me predicted, for now no PCIe 3.x advantage - http://www.hardwarecanucks.com/forum/hardware-canucks-r... while I appreciate the "few caveats" I'm not expecting any real improvements for quite sometime - we'll see...