For now, I have 1GB DDR2 667 (2x512mb), Pentium 4 3.0Ghz Hyper Threading, Geforce GT 430, ATX 500W psu, and was able to play COD4 Modern Warfare at highest settings, including set the AA to maximum, without lagging. Im waiting for my 2GB DDR2 800mhz that I already ordered from online shopping, so I will have 2.5GB of ram. Can I run Black Ops? Even at the lowest settings?
I know my processor bottleneck the graphic card but, at least, will it run? Smoothly?
Probably not, as you say, the CPU and graphics are the bottleneck in your system. Extra memory doesn't always make things run smoothly. Extra memory always helps but I dont think you will see a big improvement in your system.