Plz tell me out of HD 4890 and HD 5770 which is better ? Because as such HD 4890 is bit older than HD 5770 but still it is having a higher price tag ? Why ? And which is the best decisive factor for selecting a graphics card core clock or something else I can look for ??
If you don't care about directx 11, you can go with the 4890 which will have higher frame rates generally. If you want directx 11 which will give more eye candy when games start using it, get the 5770.
Check out some reviews on the two and go from there.