Download Everest. You can get it at majorgeeks.com site. Run the cpu benches on there. See if the cpu runs at its suppose to speed when its asked to do so by a application.
I used AIDA64, replacement of Everest, but I couldn't find how to run CPU benches, but under stress testing of the CPU where it brought the load to 100%, the CPU heated up, fans speed up, but it was still running at 1.6 ghz (266x6 instead of 266x9) according to CPUZ and CPUID.
And how do I update my BIOS, mine is from 07 now and maybe a never version has more settings.