I’ve been generally thrilled with performance after turning on hyper threading and dialing back my i7 6700k overclock to 4.4 GHz, but there’s one remaining annoyance: from time to time my CPU usage, which is normally around 50-60%, shoots up to 100% for about 5 seconds (with my fans spooling up as the temperature spikes, although not above 80C) and then goes back down. While this happens FPS goes from a smooth 60 FPS in GA aircraft down to a stuttery mess in maybe the teens, and then recovers.

Hard to pin down exactly what it is — time compression makes it happen more often, so seems like it’s probably related to terrain loading. Hills/mountains also seem to correlate with it more often than really flat terrain. Sometimes it doesn’t happen for 30 minutes, sometimes it happens every 5 minutes.

Anyone else seeing this? Any idea how to mitigate this? Is this just something Asobo have to patch to make CPU load more even?

James

I had this before, resolved by disabling the rolling cache in the Data settings.

44 minutes ago, honanhal said:

I’ve been generally thrilled with performance after turning on hyper threading and dialing back my i7 6700k overclock to 4.4 GHz, but there’s one remaining annoyance: from time to time my CPU usage, which is normally around 50-60%, shoots up to 100% for about 5 seconds (with my fans spooling up as the temperature spikes, although not above 80C) and then goes back down. While this happens FPS goes from a smooth 60 FPS in GA aircraft down to a stuttery mess in maybe the teens, and then recovers.

Hard to pin down exactly what it is — time compression makes it happen more often, so seems like it’s probably related to terrain loading. Hills/mountains also seem to correlate with it more often than really flat terrain. Sometimes it doesn’t happen for 30 minutes, sometimes it happens every 5 minutes.

Anyone else seeing this? Any idea how to mitigate this? Is this just something Asobo have to patch to make CPU load more even?

James

Did it look like this?

4 minutes ago, MrFuzzy said:

I had this before, resolved by disabling the rolling cache in the Data settings.

Thanks I am trying this now...

Yes, it does look like that. I’ve already disabled the rolling cache, though, so that’s not the issue.

James

28 minutes ago, honanhal said:

Yes, it does look like that. I’ve already disabled the rolling cache, though, so that’s not the issue.

James

Yea, I just tried disabling and deleting rolling cache, relaunched the sim and same thing. Every 5 mins or so I see a spike for a few seconds...then back to normal good performance...

37 minutes ago, honanhal said:

Yes, it does look like that. I’ve already disabled the rolling cache, though, so that’s not the issue.

James

So you want to hear something odd? I use the task manager to monitor CPU and GPU for testing. When the spike happens, if I have the resource manager or task manager on top of the sim, even when the CPU is spiked, I don't lose frames and I can pan around freely without stutter. If I click into MSFS while spiked, I drop to 17-25 fps, alt-tab back to resource manager, back to 30 fps...how odd.

So, what's more, if I set the sim to LOW settings across the board, it still happens...

8 minutes ago, cwburnett said:

So you want to hear something odd? I use the task manager to monitor CPU and GPU for testing. When the spike happens, if I have the resource manager or task manager on top of the sim, even when the CPU is spiked, I don't lose frames and I can pan around freely without stutter. If I click into MSFS while spiked, I drop to 17-25 fps, alt-tab back to resource manager, back to 30 fps...how odd.

Sounds to me like you would benefit from the processor scheduling tweak to prioritize background apps in Win 10.

https://reddit.com/r/flightsim/comments/idmdqq/update_msfs_2020_stuttering_when_window_focused/

Dont forget to change it back when not flying.

3 minutes ago, cwburnett said:

So, what's more, if I set the sim to LOW settings across the board, it still happens...

Is HT enabled, heard it helps

Is Live weather enabled when this is happening?  I wonder if it might have something to do with the weather updating.

Changing his processor scheduling will probably bandaid this since he’s not experiencing stutter with another window than MSFS in focus. If it would be a lack of hyperthreading or issues with weather causing this it wouldn’t matter what window he has in focus. It would be bad anyhow. 
 

Check my reddit link above.

27 minutes ago, TheRandomGuy said:

Changing his processor scheduling will probably bandaid this since he’s not experiencing stutter with another window than MSFS in focus. If it would be a lack of hyperthreading or issues with weather causing this it wouldn’t matter what window he has in focus. It would be bad anyhow. 
 

Check my reddit link above.

Thanks, I had read about this, but the symptoms didn't align with mine. Anyhow, I gave it a go. It does somewhat improve FPS in-game when the spikes happen. So, the CPU spikes still exist, but with the 'background tasks' tweak enabled, I now only drop a few FPS instead of 10-ish. So before this 'fix' I fell to about 20 fps for the 5 seconds of the spike every 5 mins or so. Now, I only go down to 27 fps, but the stutter is still present. I then tried setting the priority for the flightsimulator.exe process to Low as also suggested, but that had no impact.

45 minutes ago, Bilal2104 said:

Is HT enabled, heard it helps

Thanks, but the 9th gen i5 and i7 don't have HT, so no dice on that approach.

41 minutes ago, w6kd said:

Is Live weather enabled when this is happening?  I wonder if it might have something to do with the weather updating.

It was, but just tested this as well and the CPU spikes appear even when set to the Clear Skies theme...

Thanks for all the suggestions...this is pretty odd.

If you have Process Lasso or another utility that allows changing the process priorities, it might prove interesting to elevate MSFS to "high" from "normal" and see how that affects the anomaly.