If you can find 2 Asus GTS 450s then I don't see why it wouldn't work but, I have 2 GTX 480s in SLI and they are not able to produce playable frame rates in new titles so I will assume the GTS 450s would be even worse. In addition, nvidia discontinued 400/500 series driver support so the last version is 391.35. I'd look for something newer if I were you.