for that price you might find a ATI Radeon HD 4670 or ATI Radeon HD 4650 or Nvidia GeForce GT 220 or Nvidia GeForce 9500GT. you wont be getting much of and upgrade. you should save up at lest £80-£120 for something much better
Did some google just now and found that there are so many types ( isotope @@") for Radeon HD 4850, 512mb and 1G in the market, is it the more mb the faster it is?
dustin_ds3000: Thanks for your detail information.
I'm wondering do I need to upgrade my CPU as well? i'm using AMD 64 X2 5000+ Black edition (3200) on Asus m2n-E SLI mobo.
the only reason you need more than 512mb of video card ram is if your monitor have a screen resolution of 1920x1200 or higher. the fastest CPU your can have in your motherboard is the Athlon 64 X2 6400+ but you would have to update your BIOS to the latest version
What games are you planning to play and at what resolutions? For most intents and purposes the 512 MB version of the card shouls be fine.
Is your CPU overclocked? Since it is a Black Edition CPU it has a pretty decent OCing potential. So overclock it to about 3 GHz + and there should be no bottleneck on the HD 4850. Even at stock it should do OK.
Well, then I think you'll have to spend on a much better card for Crysis 2 at that resolution. The HD 4890 will also be stretched to the limit when playing Crysis at 1920x1080. You'll just about get playable framerates with all settings to Very High. So the HD 4850 should be definitely out of the equation.
And your CPU will bottleneck the HD 4890 and better cards.
I suggest that you wait a while and spend on a new gaming rig altogether.
COD 6, Bioshock 2, etc. should however run perfectly on the HD 4850.