I recently got a system with a GA-M68MT-S2 motherboard with an Athlon II X2 255 CPU. I am currently running Windows XP x64. I am considering CPU upgrades options. The highest end CPU supported is a FX-8140. My concern is given the known issues with the Windows Scheduler and the Bulldozer Architecture, would an Athlon II X4 CPU be a better choice. I know there was a patch for Windows 7 to address this, but there is no such patch windows Windows XP x64 AFAIK. Looking to get opinions on this.

Thanks!