My new system is dedicated to flight sim and I'd like to optimize it's operation for MSFS 2020. Would I do better with HT turned on or off... or would it not matter? That said are there any other BIOS or Windows settings I should be using? I haven't bothered to try to overclock, and frankly, I'd like to keep it simple. But I'd try something that's not too complicated. 

Edited February 14, 20233 yr by odourboy

Always off

I tried it both ways. I did not notice any difference.

 

HT off--the OS will prioritize threads first to the 8 P-cores, then to the 16 E-cores, and only then to the HT virtual processors if they're enabled.  I think HT, in this case, needlessly divides the cache memory available to the P-Cores for threads that can easily be serviced by one of the available physical cores...and it generates unwanted extra heat on the p-cores as well.

 

I turn HT off in the bios on the physical core that will run the main thread and leave it on on all the other cores. I have a 10900K which has 10 physical cores. MSFS runs on core9. In the bios under hyperthreading there is a by core option. Select this option and then leave HT on on core0 to core8 and turn it off on core9.

Pretty sure the core the main thread decides to use, if you do not assign it a core manually, changes.

HT on for my 13900kf. Running at 5.5-4.8 Ghz

Also my 9900K running at 5.0 with HT on.

If you can handle the heat HT on is better.

 

Edited February 14, 20233 yr by GSalden

Never turn off HT. If you have issues, use a mask to get rid of the efficiency cores which can cause stuttering in some cases due to their nature (in MSFS).

Let the P-Cores and their HT do the job.

So, I finally caved today and upgraded my machine.

Z790 motherboard, DDR5 Ram, ATX 3.0 Power supply, and a 4070Ti.

Running at stock with all cores active (HT On)

Using Frame generation, I'm getting about 110/120FPS, 1440P Ultra settings with FSLTL at recommended settings at KBOS.

Which is to say: Why would I mess around with the bios, if this is my new MSFS reality with everything at stock?

Edited February 14, 20233 yr by HiFlyer

If you have heat issues with HT on, your cooling solution is simply rubbish and not suitable for the CPU, end of the story.

it was always HT off for me ( 9900k) but been turned on for a couple of months now must say system seems a little snappier , just turn down the OC to 5.0 , waiting for reports of the 7...X3D then decide either  to stay with intel or jump 

Always ON on my Ryzen5600x

Even noticed a degradation when I made some tests with it OFF... Nah!

Edited February 14, 20233 yr by cagarini

My 13900 runs better (in MSFS) with hyperthreading off.  It was generating more heat with it on and it was approaching the thermal throttling limit, if not hitting it, and this is with water cooling!  These chips run hot to the degree that attempting any overclocking is a waste of time in the standard configuration. 

I also disabled all but 4 of the 16 E-cores, as having that many is basically useless unless you are doing video processing or something similar.  I have also heard that the cache then gets distributed among the remaining P and E-cores, which as we know, extra cache helps MSFS performance - that is why the AMD x3D chips do superbly well in MSFS.

The reason I keep 4 E-cores is because I use Process Lasso to assign all of my other background processes to these during MSFS, which then gives MSFS free reign on 8 P-cores, which is enough for MSFS, as they can hold a higher GHz for longer without hyperthreading enabled.  It appears that although MSFS uses multi-threading, it is still very much a user of a single core, or main thread, and 8 is easily enough cores to for it, especially at 5.8GHz.  In fact, it seems cores 2 and 5 on mine run at bout 90-95% in MSFS, with all the others at about 40-50%.

After testing different configurations, this is definitely the best I have come up with, and gives me a smooth experience in MSFS at 60 fps in the main, at 4k DLSS ultra settings.
The best flight simulator experience I have ever had actually.

Just some side notes.  I assign all eight P-cores to MSFS in Process Lasso.  The only other thing remaining on the P-cores is windows explorer processes, as it is advised not to move those.  I have managed to under-volt the 13900 slightly, which has also reduced the temps.  It has been completely stable with no CTD's or blue screens for months (which last happened when pushing the limits).

This has given me by far the smoothest experience in MSFS, and cool and quiet as well after activating DLSS for the GPU.

Strangely, the 12900 I used previously worked better with hyperthreading, but it was flat-lining at 100% usage in MSFS at my settings, causing slight stuttering / fps drop.
So this isn't a 'one size fits all' solution, and I was quite surprised when disabling hyperthreading worked better for me, as I have always been an advocate of it until getting the 13900.

Edited February 14, 20233 yr by bobcat999

42 minutes ago, bobcat999 said:

My 13900 runs better (in MSFS) with hyperthreading off.  It was generating more heat with it on and it was approaching the thermal throttling limit, if not hitting it, and this is with water cooling!  These chips run hot to the degree that attempting any overclocking is a waste of time in the standard configuration. 

I also disabled all but 4 of the 16 E-cores, as having that many is basically useless unless you are doing video processing or something similar.  I have also heard that the cache then gets distributed among the remaining P and E-cores, which as we know, extra cache helps MSFS performance - that is why the AMD x3D chips do superbly well in MSFS.

The reason I keep 4 E-cores is because I use Process Lasso to assign all of my other background processes to these during MSFS, which then gives MSFS free reign on 8 P-cores, which is enough for MSFS, as they can hold a higher GHz for longer without hyperthreading enabled.  It appears that although MSFS uses multi-threading, it is still very much a user of a single core, or main thread, and 8 is easily enough cores to for it, especially at 5.8GHz.  In fact, it seems cores 2 and 5 on mine run at bout 90-95% in MSFS, with all the others at about 40-50%.

After testing different configurations, this is definitely the best I have come up with, and gives me a smooth experience in MSFS at 60 fps in the main, at 4k DLSS ultra settings.
The best flight simulator experience I have ever had actually.

Just some side notes.  I assign all eight P-cores to MSFS in Process Lasso.  The only other thing remaining on the P-cores is windows explorer processes, as it is advised not to move those.  I have managed to under-volt the 13900 slightly, which has also reduced the temps.  It has been completely stable with no CTD's or blue screens for months (which last happened when pushing the limits).

This has given me by far the smoothest experience in MSFS, and cool and quiet as well after activating DLSS for the GPU.

Strangely, the 12900 I used previously worked better with hyperthreading, but it was flat-lining at 100% usage in MSFS at my settings, causing slight stuttering / fps drop.
So this isn't a 'one size fits all' solution, and I was quite surprised when disabling hyperthreading worked better for me, as I have always been an advocate of it until getting the 13900.

I do not agree as I ran the 13900kf with HT off at first and it run very smooth, but when I started running it with HT on everything became buttersmooth.

Regarding using specific cores it is better to use a batch file to assign cores to a certain app than PL as PL controls the cores after an app has started. Starting an app right away with specific cores runs more stable.

At the P3D forum this has been discussed a lot including testresults.

Edited February 14, 20233 yr by GSalden

19 minutes ago, GSalden said:

I do not agree as I ran the 13900kf with HT off at first and it run very smooth, but when I started running it with HT on everything became buttersmooth.

That is fine not to agree.  It isn't compulsory.   I am just adding my personal experience as the OP has asked.   
I will just add that your setup is very different to mine from what I can see from your previous posts, and I don't use AI traffic etc. 

So it is important not to compare apples to oranges.  It is not just a case of running MSFS and comparing it - it depends on how you are running it. 
I only know what I see, and it is smooth, cool, and quiet, and the last two are also a major consideration to me, as I tend to be using MSFS in the bedtime hours while the wife is asleep.  

Edited February 14, 20233 yr by bobcat999