In comparisons of the AMD HD 6990 and Nvidia GTX 590 the best performer depends on the particular game being played, so I was wondering if there are any motherboards that allow you to have both AMD and Nvidia GPUS on the same Mobo at the same time and easily switch between the AMD and Nvidia GPUs to suit the particular game being played?
Your a noob yet your considering getting a gtx 590 AND a 6990. Hoping you are asking out of curiosity. Think you could but the setup to be able to hold the two massive cards would be expensive. Sli 580's or crossfire 7970's would smoke them. The difference would only be a couple fps if that so it wouldn't be worth it. Also the 590 would have physx.
As far as I know, the only motherboards that support both ATI and nVidia GPUs being used at the same time are those with the Lucid Hydra chip. A new technology may have come out, but I don't think so. Last time I checked, only certain combinations worked well enough. On a few sites, regular CrossFire and SLI didn't work, which means in the case of the HD 6990 and GTX 590 (both powered by dual chips and thus using CrossFire and SLI respectively) would most likely not work or just present very low frame rates.
As far as switching between GPUs goes, the only GPU switching technology I'm aware of is nVidia's Optimus, but that's only laptops and with Intel GPUs as secondaries as far as I know.
The Lucid Hydra motherboards by the way are all from MSI, and I only know three which exist - P55A Fuzion for the LGA 1156 platform, Big Bang Fuzion for the LGA 1366 platform, and 870A Fuzion for the AM3 platform.
Yep. Stay away from both.
The basic problem with your idea is that it wouldn't make sense to buy both of those expensive cards and leave one idle. You could just spend $1100 on two 7970s and have insane performance at a better value, if you can call it that, by making use of both at the same time.