I think you could use your $90 more wisely than a 4670 or 8800GS. As RazeryBandit mentioned the 5670 would be much better. However, my questions is what does the rest of your system look like? PSU, CPU, etc? If your PSU can handle it there are better options, however if it is a stock OEM unit, you may want to look at the 5670, it is better than either of the options you mentioned.