i have an opteron 170 (which is an x2 with bigger cache and 2.0GHz each core). there are some known problems with amd dual core processors. try 2 things:
1. download the appropriate driver from the amd homepage (exe file)
2. amd has a tool called "dual core optimizer" http://www.amd.com/us-en/Processors/TechnicalResources/0,,30_182_871_13118,00.html try it. solves several timing problems.

might be your notebook graphics card as well, as they tend to be generally slower.