Ive currently got a Pentium 4 2.0ghz with 600mb ram, and a nvidia ti4400 graphics card. Im probably going to be upgrading to an athlon 64 3200 with 1gig of ram. If I didnt upgrade the gfx card would it be a major bottleneck for the system? If so, what card would be recommended, i can probably afford £150 budget for one.