http://www.microsoft.com/windowsxp/using/64bit/russel_exploringx64.mspx
Doesn't Windows XP x64 support the AMD Athlon 64 X2 this came as a great suprise to me.
From AMD, this includes the Athlon 64, Athlon 64 FX, Mobile Athlon 64, Turion 64, and Opteron processors. From Intel, this includes the Xeon with EM64T and Pentium 4 with EM64T processors. The two architectures are binary compatible, allowing Windows XP Professional x64 Edition to use a single version to support both.
Doesn't Windows XP x64 support the AMD Athlon 64 X2 this came as a great suprise to me.