I'm saying go for 2GB, it's not that expensive and if Portal 2 needs more than 1GB on very high settings with 4x MSAA, I imagine other games will too. If you're spending $2k+ on a nice machine you may as well not only future proof it but make sure it can't be bottlenecked as it is. barefeats Portal 2 results Notice the 5870 1GB being majorly bottlenecked at 2560x1440 whilst the 2GB 6970M isn't bottlenecked. EDIT: There was a patch released for Portal 2 which improved performance with MSAA, and the 5870 now has a higher frame rate than the 6970M in that same test. So, it may not have been the VRAM bottlenecking it. I still recommend 2GB though.