Ok i finally got it stable at 3445.7 MHz (all four cores).
Problems were:
1. Extreme dust inside graphics card cooler (that i didn't see before)
2. Memory controller can't do more than 420MHz when used with Quad core (but can do 460MHz with Dual core for some unknown reason)
3. CPU Volt drop was a little high but then i fixed it.


All settings in quake 3 are on high, anistropic filtering is at 16X.. @ 1280x1024.

Comparison:

