I just purchased an Intel Quad Core Q6600 overlocked to 2.6GHz. I ran a modeling benchmark test on it and the results took about 5.5 hours. I then ran the same modeling on an AMD Opteron 2.4GHz and it took 4.5 hours. Both systems have 4GB of RAM in them. Keep in mind this is not a graphical modeling, but modeling using calculations of matrices.

The Intel Quad core is running Ubuntu Linux 6.10 and the AMD Opteron is running CentOS 4.4.

From the specifications white sheet, the Quad core seems to surpass the Opteron. Why is the Opteron faster?

I left out some details. The AMD Opteron dual core is running Cent OS 4.4 64-bit edition. I am running the Intel Quad Core on the 32-bit version. Is that the difference?

Centos and RedHat 4 have very good performance. What I see inside VMWARE guest os RH4 even ran faster than host OS.