Fsb parity is a function of the motherboard; check the bios to see if you can disable it. Also list your motherboard brand and model number, and what you do with your pc. The money spent may not give you the performance boost you're looking for.
I don't have the motherboard brand/model in front of me, but I'll try and find it.
The machine is a renderBoxx 10100 from 2/2007. It's part of a small render farm doing Maya rendering, using PipelineFX Qube as the queueing software. Runs Maya both in batch and interactive mode, but this is strictly a server machine (no GUI).
So, it's very FP intensive with a fair amount of I/O as well. Reading in large models (locally) and then writing 1-2MB frames every 60s or so (Networked RAID array, MetaLAN over 1GB ethernet). According to various benchmarks, the move from a 1.6GHz E5300 to a 2.5GHz E5400 or X5300 *should* yield a pretty significant gain. Perhaps 50-100%. At $250-300/processor that would be very worthwhile to us.
I realize that the CPU is only one factor involved. The MB has a 1333Mhz FSB and 4GB DDR2 667 (ECC) memory. Memory usage is typically low, although Maya interactive mode occasionally goes into a garbage collection cycle. These are dual CPU machines with 2 nodes per box. I'll try and find the motherboard make/model and the BIOS info. I'll be swapping a hard drive on Tuesday and will look for FSB partity settings. Thanks!