while experimenting with using lesser no of cores using the taskmanager affinitymask setting for fsx.exe got some strange results.setting on heathrow with 9-15fps, q9550 @rated.initialy core0 is consistent at 100% with other 3 intermittently sometimes touching 100 for few seconds. then on disabling any of the core(s) remaining go to a constant 100 as expected but what comes unexpected is there's almost no drop in fps from 4 to 3 to 2 to 1 core.selected all cores to return to initial settings then none of the cores touched 100. they seem more or less equally loaded hovering 65-85 and sometimes 100 all 4 at once but fps still unchanged. restarted taskmanager but results same. a 3rd party core temp utility shows the same. also the core0 temp that was intitialy highest now comes close to others. retarting fsx again gives core0 at 100% rest used lesser.is what taskmanager showing true i.e. all cores used equally by fsx? also why no fps drop even after moving down to single core?

while experimenting with using lesser no of cores using the taskmanager affinitymask setting for fsx.exe got some strange results.setting on heathrow with 9-15fps, q9550 @rated.initialy core0 is consistent at 100% with other 3 intermittently sometimes touching 100 for few seconds. then on disabling any of the core(s) remaining go to a constant 100 as expected but what comes unexpected is there's almost no drop in fps from 4 to 3 to 2 to 1 core.selected all cores to return to initial settings then none of the cores touched 100. they seem more or less equally loaded hovering 65-85 and sometimes 100 all 4 at once but fps still unchanged. restarted taskmanager but results same. a 3rd party core temp utility shows the same. also the core0 temp that was intitialy highest now comes close to others. retarting fsx again gives core0 at 100% rest used lesser.is what taskmanager showing true i.e. all cores used equally by fsx? also why no fps drop even after moving down to single core?

The primary simulation thread runs on one and only one thread in FSX, and the core running that one usually stays at near 100% unless the sim is paused or in menu mode etc. Any additional cores are used to handle texture loads and autogen scenery. Depending on what the sim was doing as you switched config, it could be that there wasn't much texture/autogen workload at the time, or it could be that the texture/autogen work was being done, but more slowly and spread out over more frames than before, or the texture loads were prioritized, with more distant textures rendered at a lower mip level (and left blurry).I suspect that once you preempt FSX's load-time process affinity with task manager, it does not revert to it's pre-intervention state when you get around to re-enabling the cores. So what you're probably seeing is the OS (Windows) swapping the primary FSX thread around to different cores rather than leaving it on one--it will appear as an equally-shared load across the cores, but it will cause some decrease in performance due to the overhead involved with incessantly swapping the primary thread around.RegardsBob ScottColonel, USAF (ret)ATP IMEL Gulfstream II-III-IV-VColorado Springs, CO

Hi BobThanks for the expert reply. could you explain thread swapping a little furtheralso as fsx is using only core0 mostly, I was wondering if it will result in its relatively high wear and tear (running at highest temp)if so is it possible to make fsx select a core randomly to run primary thread each time fsx starts?