I think you are confused. The GT 640 is a video card(gpu) not a motherboard(the motherboard is what the cpu, ram, and video card all plug into). 2 video cards that use the same gpu(gt 640 in this case) will usually perform about the same if the specs are similar. There may be some performance differences depending on the type of vram used, if the card is factory overclocked, etc. The gt 640 can use 2 types of vram gddr3 and gddr5 a card using gddr5 will be faster than a card using gddr3. Don't think you will have to worry about a factory overclock as companies rarely oc entry level cards like the GT 640.