Hi there
I hope you guys can help...
I upgraded from x800xl 256MB to x1900 512MB and have problems running games
I mean graphics get choppy same here with dxdiag when I run DX test I see the cube spinning but it seems to lag every few seconds.
 
System spec
 
Abit IL9 PRO mobo
Pentium 4 HT cpu
2 x 1 GB Corsair Twinx ram
hdd & dvd burner at IDE
 
When I had x800 everything worked fine and I could run Counter Strike at 300fps, and now I can't run SimCity 4 cuz it's choppy
 
At first I thought it's a power supply problem but I upgraded to Ultra 600W delivering 35A at 12V, way more than requirements
also upgraded directX
 
I checked several different drivers: original and modified, no effect
 
System works well, youtube videos full screen too.
I have XP pro, and windows detects card as it should
 
I got this card for free, maybe it's just defected
 
Drawing a blank, please HELP

Try running ATITools and run their artifact scanner. If it finds artifacts it could be bad memory.
 
And look at the CCC information page and se what the clock speeds are set at. If its too low might just be a bad card and you might want to go back to your old one.

Did you bother cleaning out the drivers first?  
Use driver cleaner pro first.