what thermal grease did you use?  did you clean all the old stuff off.  Be aware that the lids on cpu chips are usually somewhat concave on the top, recently had to add a drop of thermal grease to regreased cpu that was running too hot even idleing.  solved it completely.  current processors are large enough and concave enough to require more grease than seems right to someone experienced with older electronics.  There is a huge difference between common silicone grease suitable for amp's and higher performance products.   basic thermal grease is a sick joke for a cpu.   Some of the better stuff is stiff, and overpriced thanks to mad gamers and other overclockers.   I Love the pk-3 stuff with nanoaluminum but it has to be fairly hot to spread well, then again it takes 2-3 minutes to settle and markedly lowers cpu temps when heavily loaded.  Previous favorite was ceramax. ignore the hype and any brand that doesn't provide the thermal resistance or conductivity (which are inverses, of course so either is fine for choosing, thermal conductivity should be high, thermal resistance should be low).  Most are insulators at low voltages due to surface oxidation and the oil etc, on power wiring probably not a good idea. most greases need to bake and be through power cycling a few times for optimum performance, they thin when warm.  with my particular favorite grease it only takes 2-3 minutes powered on to reach optimum performance.  my preference also avoids wasting silver and just uses extremely fine aluminum powder and some additives. And what cpu has any one seen working without a heatsink in the last ten years other than some system on a chip or very low end embedded processor?  Seriously,  unless I've been in hibernation some how i doubt it. mad.scientist.at.large (a good madscientist) -- God bless the rich, the greedy and the corrupt politicians they have put into office.   God bless them for helping me do the right thing by giving the rich my little pile of cash.  After all, the rich know what to do with money.  19. Apr 2018 20:33 by r030t1@gmail.com : > On Thu, Apr 19, 2018 at 9:26 PM, Corbin Bird <> corbinbird@charter.net > > wrote: >> What are the Dell system specs? >> >> ( Heatsink on a CPU? .... How old is this system ? ) >> > > Dell Precision T7600, two 16 thread Xeons, 192GB of RAM, two Quadro > cards and a Tesla card. > > The system is a few years old at this point. Old enough that the > thermal compound could have hardened, which is why I replaced it. > >> On 04/19/2018 08:22 PM, R0b0t1 wrote: >>> I was compiling Gentoo, as is custom, but found my old new server to >>> be thermal cycling wildly. The fans will turn on full blast and >>> machine check errors will be generated if I use approximately more >>> than one third to half of the cores. The cores then throttle >>> themselves, only to immediately overheat once the throttle lifts. This >>> seems to persist on Windows, though Windows seems to be much more >>> conservative in its CPU usage, and triggers MCEs less. >>> >>> Any suggestions? I repasted the CPU and heatsink interface, and the >>> machine is not loaded with dust. It was hardly ever used. The MCEs >>> seem to be a "normal" part of operation, though less normal on >>> Windows. >>> >>> Is there a way to at least mimic the conservative CPU usage that >>> Windows exhibits? >>> >>> Cheers, >>> R0b0t1 >>>