The current client is dx9 and performance is CPU limited by the main thread in populated areas. After much experimenting, I found that with my gtx780 and i5-2500k @ 5ghz, the best performance is obtained in windows XP 32bit sp3. I can hold 60fps with the maximum amount of characters in view in m.dhona at 1680x1050 with everything maxed except shadow resolution. The exact same configuration in a highly-tweaked windows 7-64 bit can maintain only 45fps. The new benchmark also performs the best with XP in dx9, but with dx11 win7 pulls ahead with the same settings (but only by a few %).