Hey all,After my copy of FSX came down with some nasty periodic stuttering issues (every 70 seconds the framerate would drop to around 5 FPS or so for about 5 seconds) I tried changing a variety of settings to make it go away, to no avail. Finally, I happened on this thread: http://www.pcmech.com/forum/gaming-benchmarks/192410-fsx-optimization.html, which suggested that disabling multicore (by setting an affinity mask setting that only uses one core) would remove stuttering. That seemed unbelievable, but at that point I was desperate so I tried it. Lo and behold, FSX is smoother than it has ever been and there is little, if any, drop in performance as far as terrain rendering and such goes. The stutters every 70 seconds are gone. The fact that this is happening with FSX using literally half the CPU power it was before (I checked it in the performance monitor--now it shows 50% CPU usage instead of 100% with multicore) is crazy.Although performance is decent, now (of course) I'm feeling greedy. Is this seemingly paradoxical result just a limitation of FSX, that for whatever reason multicore is inherently massively inefficient and there's a substantial dead weight loss in performance and (especially) stability that can only be made up for with raw horsepower? Or is there some way that I can perhaps get FSX to better utilize the CPU power I have available (since having FSX use both cores without some additional tweak doesn't work well)?Any thoughts are much appreciated. I realize there's increasingly few of us using dual core machines to run FSX, but I figured it was worth asking anyway.Best,James

You could assign trackIR and perhaps add-ons to core#1. That would free up core#0 for fsx a bit.There could also be a tweak if you know the AffinityMask=x, x being a number for making fsx handle botth cores, and avoid those thread collisions I suspect you were experiencing. Someone will know the number, I only remember the four-core no. You could try Bojote a.k.a. ******* Altuve's configomat, and see if it works any wonders.Bjorn

Hey all,After my copy of FSX came down with some nasty periodic stuttering issues (every 70 seconds the framerate would drop to around 5 FPS or so for about 5 seconds) I tried changing a variety of settings to make it go away, to no avail. Any thoughts are much appreciated. I realize there's increasingly few of us using dual core machines to run FSX, but I figured it was worth asking anyway.Best,James

You need to find out what is causing your periodic slowdowns. There is likely a program running in the background that takes priority every 70 secs. Use procmon or such to monitor what is running. You would get better texture loading performance if you have both cores enabled. The raw fps performance is dependent on only one core. BTW the advice you quote dates back to 2008.. and SP1.If I were to guess, I would have a look at the Java updater, it is known to interfere..Control Panel / Java / Advanced / Misc / uncheck Java Quick starter

The C2D procs also respond ok to overclocking. I remember having my E6600 bumped up to 3.2 - not very fast, but it made quite a difference to how FSX ran. There are lots of sites devoted to doing just that.

I managed to check out the situation with both Windows' resource monitor and procmon, and to my surprise found that it was not a case of a system process taking priority every 70 seconds. Rather, FSX was simply increasing to 90-97% usage every 70 seconds, which was apparently causing stutters. I'm really not sure how to proceed. It would be great if I could limit FSX to 90% of system resources (or even 95%), but otherwise it might be the lesser of two evils to have FSX run on my second core and let system processes and ASE run on the first. I don't really know what else to do! Clearly, my system isn't ideal for FSX, but I wish there was a better solution.

The C2D procs also respond ok to overclocking. I remember having my E6600 bumped up to 3.2 - not very fast, but it made quite a difference to how FSX ran. There are lots of sites devoted to doing just that.

I agree my e8500 has been increased from 3.16ghz to 4ghz it made a hell of an improvement!!

Also, I should mention that I am already overclocking the CPU, which does help with overall performance but not stutters.

I managed to check out the situation with both Windows' resource monitor and procmon, and to my surprise found that it was not a case of a system process taking priority every 70 seconds. Rather, FSX was simply increasing to 90-97% usage every 70 seconds, which was apparently causing stutters. I'm really not sure how to proceed. It would be great if I could limit FSX to 90% of system resources (or even 95%), but otherwise it might be the lesser of two evils to have FSX run on my second core and let system processes and ASE run on the first. I don't really know what else to do! Clearly, my system isn't ideal for FSX, but I wish there was a better solution.

OK, something to note... Every minute or so, FSX recalculates the lighting of the scenery.This drives up CPU usage for a brief moment. The best way to deal with this is to have thebase load low enough so that it does not become noticeable. I turn off all freeway traffic as an example.If you run with FPS unlimited, the impact will be more pronounced than if you run with FPS limited.

The affinity mask setting is simply a decimal equating to a binary number. Some examples:1 = Binary 1 (use 1 core on a dual core machine - core 0)2 = Binary 10 (uses core 1 on a dual core only, leaving core 0 free)3 = Binary 11 (uses both cores on a dual core - default setting anyway under SP2)14 = Binary 1110 (uses cores 1, 2 & 3 on a quad core leaving core 0 to run the background processes -much smoother overall)15 = Binary 1111 (uses all 4 cores on a quad core - default setting anyway under SP2)You will note that the binary numbrs are reversed. i.e. 1110 means core 0 is unused)Binary 111 (7 in decimal) would actually use cores 1, 2 & 3 leaving core 4 free.So I always use 14 on my quadcore, but would not suggest mesing about with the affinity mask setting on a dual core as you probably need both cores to run fsx in such a case.Does that make sense?IAN

I managed to check out the situation with both Windows' resource monitor and procmon, and to my surprise found that it was not a case of a system process taking priority every 70 seconds. Rather, FSX was simply increasing to 90-97% usage every 70 seconds, which was apparently causing stutters.

If you are flying FSX in windowed mode, with fps locked at 30, and watch the Windows Task Manager / Performance tab, you can watch the load on both cores. Your overall CPU usage will be between 50 and 100%.Core0 will be running at 100% and Core1 will fluctuate, depending on scenery loading to be done.Try turning off ground shadows and turn down water to 1Xhigh, and as said before traffic if your aim is smoother performance.

It looks like my system just isn't powerful enough to avoid this issue...even out to sea with no other traffic, complex airplanes end up with single-digit frames every 70 seconds or so (dropping from 25 FPS). As I said, running FSX on a single core actually solves the stutter, albeit at the expense of terrain loading speed. Very frustrating!

Have you tried changing priority? CTRL-ALT-DEL to bring up the task manager, 2nd tab w. all the processes running, find fsx.exe, right click, change priority to high, ignore warnings, fly.B

Mystery solved! Upon yet another inspection of resource monitor, I noticed that the issue was that my CPU's maximum frequency was dropping to about a third of its normal value periodically, corresponding to the stuttering. Turns out my laptop CPU was overheating and downshifting to prevent damage! (This is probably what I had coming to me for trying to use FSX on a laptop...) Hopefully after I clean the thing out the problem will be reduced, at least.Thanks to everyone for their help!

Mystery solved! Upon yet another inspection of resource monitor, I noticed that the issue was that my CPU's maximum frequency was dropping to about a third of its normal value periodically, corresponding to the stuttering. Turns out my laptop CPU was overheating and downshifting to prevent damage! (This is probably what I had coming to me for trying to use FSX on a laptop...) Hopefully after I clean the thing out the problem will be reduced, at least.Thanks to everyone for their help!

OK, that was a simple cause: Hardware, not Software!Thanks for letting us know!