There is somewhat of a case that can be made for stability with xeons vs i7’s, but only in regards to overclocking and the xeon platform using ECC memory. Non-ECC memory does introduce a minor level of possible instability.
As far as the CPU’s themselves though, the sandy bridge-E chips were xeons, but didn’t make the cut. They were all 8 core chips designed to run at 100% load at a certain V-core and temp.
When they mass produce them, not all chips come out equal. Some leak voltage, and will thus pull in more voltage to run at 100% load which makes them run hot. Intel takes these chips, disables 2 cores and some L3 cache and then repackages them as i7’s or lower end xeons, sometimes clocking them higher than they were originally going to be. Some chips are way off the mark and others are just barely.
Either way, disabling cores and bumping the clock speed up slightly ensures that the chips can maintain stability. The ones that barely didn’t make the xeon cut are champion overclocking CPU’s and will run more stable than the chips that were too far from intel’s criteria.
We can’t enable the disabled cores, but we can overclock the existing cores. If you could take the highest end xeons and do whatever you wanted with them in regards to disabling cores and overclocking, they would perform faster, run cooler, use less voltage, and be more stable than the i7 or lower end xeon CPU’s if they were configured the same way.
All that said, in the real world an overclocked i7 can be made stable by adjusting settings in the BIOS and adding better cooling. You can reach 100% stability with the exception of non-ECC memory

