I used to have, a ATI Radeon 5450 1GB GDDR3
this was okay, but i could only play at 1366x768, Low FX, as this card was only built for gaming without many shadows as i worked out when trying to play games like Modern Warfare and San Andreas at High/Very High
I now have a ASUS ATI Radeon 6670 1GB GDDR5,
there is a massive differences as now i can play GTA SA all maxed out, for example 1366x768, FX: very High and Anti Analising at 3, also now i can play gta iv, and many of the cods at medium to high, i cant wait to get a Quad core the game would be so much better FPS, but my personal opinion is GDDR3 Dont cut it for me anymore its always going to be GDDR5.