30fps, in 25 man raids, a ball ache. You sir, have very sensitive balls.
I heal with 7fps in 25 man raids with low low detail and my balls are just fine.
Anyway, I'll beat a dead horse:
WoW is more dependant on your CPU than GPU. I'm running an ancient AGP 8x system:
P4 w/HT 3.0ghz, 800mhz FSB
2GB SD-whatever-ancient-crap-Ram @ 300mhz
NVidia 512MB 7800gt
5000-ish RPM 250gb SATA
I can turn everything on high except shadows, those are 1 notch above the minimum. I can get around 10-20fps in Dalaran, depending on player density. 30+ in old world while leveling alts, 20-ish in Outland/Northrend. I get around 20 in ICC just standing around, 30 if I min the settings. Bring on the AOE, Treants, Heroism and the lot and I tank down to ~2. After it's all over around 10.
I used to have a Celeron D 2.9-ish ghz (300 or 500mhz fsb, can't remember) in there. 25 mans were impossible, it would just choke to 0.5fps or something rediculous.