Just started using the FLOSS PHP5 Phoronix Test Suite and its associated Phoronix Live CD (for 64-bit CPUs only) for performance benchmarking & performance testing PCs.
Now you can find out if the Intel T2390 or the Intel T9300 is the fastest ? And by how much ? Go to http://global.phoronix-test-suite.com/?k=search and enter T2390 and T9300 into the processor search box and find a testset that has been run on all/both the CPUs you want to compare.
For example here’s the BYTE UNIX benchmark for a Intel PII v AMD Athlon v Intel Core i7.
See also http://www.phoronix-test-suite.com/?k=documentation