MSFS & Hyperthreading

[Donka 671]

3 hours ago, MrFuzzy said:

Thanks for pointing out that.

I was skeptical but I did a similar test in my favorite CPU limited testing environment (A310 @ EDDF25C, real time traffic) and for the first time I found the same results!

You are seeing better performance with HT disabled on the 7800X3D? Did you notice a difference in the sim?

[FederFlyer 27]

I have an i7 2.4 GHz 10-core and an RTX 3050. I don't have the thermal data, but my system always ran very hot and I routinely burned my fingers when they were near the fan exhaust. I turned off hyper-threading and my system runs noticeably cooler, the fan is not running continuously and, most importantly, no more burned fingers! 

 

[MrFuzzy 2,132]

18 minutes ago, Donka said:

You are seeing better performance with HT disabled on the 7800X3D? Did you notice a difference in the sim?

On the ground at large airports I notice the difference. It feels smoother. This is reproducible on MSFS. I tried again with a longer testing time in the same conditions.

But interestingly, some time ago I tested a different build with a 10850K @ 5 GHz and the result was the opposite. I remember that I used to get about 38-40 fps average with the A310 @ EDDF25C with the 10850K which is a much slower CPU than the 7800X3D. And in fact the result was 55 fps as soon as I upgraded the CPU! Now back to 40-45 again 😞 I can't find the old post now, CapFrameX screenshots should still be there.

Apparently Asobo is going the wrong way in terms of optimization and CPU performance. 

In Warzone 3 it seems that HT (or SMT) provides slightly better performance instead, even though here the scenario is far from reproducible. I tried two resurgence matches.

[FBW737 525]

2 minutes ago, FederFlyer said:

I have an i7 2.4 GHz 10-core and an RTX 3050. I don't have the thermal data, but my system always ran very hot and I routinely burned my fingers when they were near the fan exhaust. I turned off hyper-threading and my system runs noticeably cooler, the fan is not running continuously and, most importantly, no more burned fingers! 

 

You burned your finger off the exhaust fan air? There is something seriously wrong Bro!

[FBW737 525]

Which app are you guys using to get those bar graphs?

[FederFlyer 27]

Not burned enough to cause injury, but enough to learn to keep my fingers away from the exhaust port.

 

[bobcat999 8,550]

2 hours ago, Poppingcork said:

You have the exact same system as me.  Are you using the bios to turn off the cores or can you accomplish this via software?

BIOS is the best and simplest method.  There is some software from Intel called "Intel® Extreme Tuning Utility (Intel® XTU)", but I was fiddling with it endlessly, without much result.

So I went into the BIOS, then I think it was advanced settings, CPU (working from memory here), scroll down a bit, set all E-cores to zero, P-cores to six, turned off hyperthreading, and F10 to save and boot. 

I can promise you, even if you don't gain much performance, you won't lose any, and it will run much cooler.    Mine was mainly smoothness.  I held 60 FPS at 4k ultra much, much better. 
I can't go more than 60, as that is the maximum for my 4k monitor, but 60 FPS is fine anyway for the sim at 4k.  30 FPS is good for some of course, but I use a head tracker, so 60 is best when panning around - no judder, but I did get a bit at 30.  This is DX11, so no FG.

If you don't like it, it only takes one reboot cycle to change it back.

[fluffyflops 1,883]

16 hours ago, iFlySimX said:

Hello all! 

I decided to do some testing with my i9-9900k as I've been getting some stutters on the ground with the Fenix A320. 

I turned Hyperthreading OFF in the BIOS and it seems a lot smoother and gives me higher FPS. Is that expected, any reason why I SHOULDN'T keep Hyperthreading off?

thanks for this,  I also have a 9900k 

[MarcG 3,117]

29 minutes ago, FBW737 said:

Which app are you guys using to get those bar graphs?

CapFrameX

https://www.capframex.com/

Edited December 8, 2023 by MarcG

[Gregg_Seipp 573]

I tried disabling Hyperthreading on my i9-9900 3.1 ghz just now.  Flying the Fenix, framerates seemed to be better but the instrumentation in the plane was jerky...stuttering from value to value.  There are some settings in the Fenix config that might help with that, but could cost some frames.  So...not sure about the results.  I also see that the CPU utilization is about equal over all 8 processors at about 80%.  Maybe my system isn't quite up to it.

Edited December 8, 2023 by Gregg_Seipp

[MrFuzzy 2,132]

Pls delete

Edited December 8, 2023 by MrFuzzy

[Ixoye 1,859]

If you only use your computers for MSFS only it is probably a good idea to turn off HT, but if you run several programs in the background at the same time, it is probably best to have HT enabled.

[Donka 671]

Looks like my Asus B650 mobo doesn't offer the option to disable SMT.

[jimcarrel 688]

I'm sold  with the "HT off" thing, runs splendidly on my machine.

[FBW737 525]

I'm not going to post an image because its a pain the, but I made a HT on to HT off Comparison my 10900K system and to my surprise nearly 10% higher FPS with HT off!

I set up a static eternal view of the A330 at a gate in KLAX at 10:40am with Few Clouds theme. Used CapFrameX for a 120 second capture. did ity with HT on and HT off.

The average FPS with HT on was 34.5 and with HT off it was 37.7