I wonder - what prevents motherboards on Intel's P35 chipset to use NVIDIA SLI technology. Few days ago, I was e-mailing GIGABYTE about their motherboards on Intel's P35 chipset, asking, if I'll be able to use SLI on them... they've told me no - only CrossFire. Same with ASUS - on their site they say, that only CrossFire is compatible. I'm not a big fan of NVIDIA's chipsets and I want to use Intel's P35. Maybe it's because of legacy and only? Why ASUS P5K-E can't run SLI? I seem just not to understand that. Does it such a big difference betwene CrossFire and SLI? If you can answer that - please, feel free. Thank you.
nVidia holds the license to SLI, along with whatever chipsets they choose to allow SLI to be run on. There's nothing that physically prevents SLI on any chipset. However, nVidia doesn't seem willing to allow SLI on anything outside their own nForce chipsets. SLI is locked out by drivers, so it's possible to get around, but nVidia tends to put the kibosh on any hacked drivers like this.
Big B is exactly correct. But the only chipset that you would want to put crossfire onto that doesn't support it would be x38/48, and I think there's a few AM2 chipsets, too. SLI is only actually usefull on a board that can handle the full 32x bandwidth of two 16x pci-ex lanes. True p35 chipsets do not support this. They usually give you one 16x and one 4x bandwidth. This means that the board isn't even usefull for crossfire. The improvement you receive with 4x pci-ex bandwidth is absolutely minimal.
Thank you very much for your clearence of details, gazaway... you've amazed me. So P35 motherboards doesn't have full 32x support and X38 motherboards do have it, right? If so - will X38 motherboard raise performance (if 2 graphics cards) of SLI/CrossFire on 100%?
Still not 100% due to driver performance, BUT you will prolly get a 4x greater gain from a second GPU on a x38 than a p35.
