I have your X5DA8 motherboard and running two 2.4GHz 533MHz system bus speed processors. These processors seem to be overheating. Is this caused by chassis fans not providing enough cooling air to the processors?
It is possible that your chassis is incapable of cooling the processors adequately, but we find that majority the problem was caused by incorrect heatsink retention clip. 604-pin Xeon processors are not as thick as 603-pin Xeon processor and require a different retention clip to provide adequate tension between the heatsink and processor to effectively transfer heat. Please verify that you have the correct clip installed. We strongly recommend to use 604P clip for 533FSB CPU vs. 603 for 400FSB.