Check out ASRock > 939N68PV-GLAN cpu support list to see which processors you can upgrade to.
From the specifications for your motherboard at the ASRock website:
- - Socket 939 for AMD Athlon™ 64FX / 64X2 / 64 processors
- - Dual Channel DDR memory technology
- - 4 x DDR DIMM slots
- - Supports DDR400/333/266 non-ECC, un-buffered memory
- - Max. capacity of system memory: 4GB*
*Due to the operating system limitation, the actual memory size may be less than 4GB for the reservation for system usage under Windows® 32-bit OS. For Windows® 64-bit OS with 64-bit CPU, there is no such limitation.
- - Microsoft® Windows® 2000 / XP / XP 64-bit / Vista™ / Vista™ 64-bit compliant
I've changed the title of your thread to Best CPU for ASRock 939N68PV-GLAN Motherboard?