Just now, Wise87 said:

I thought if you have Hyperthreading off in bios then you don’t need to create AffinityMask? 

It seems that’s the case but why have I only become aware of this now after years of flying P3D?

Logically if you only have physical cores present and no logical ones they’re all assigned by default. You have to tweak things with HT enabled.

4 minutes ago, Ray Proudfoot said:

It seems that’s the case but why have I only become aware of this now after years of flying P3D?

It may just be due to some rearrangements of threads new in P3D5.2 which gets two crucial threads competing for time on one CPU, so simply splitting them to separate real CPUs stops (or markedly reduces) that conflict.

Pete

 

Edited June 19, 20214 yr by Pete Dowson

@Pete Dowson, is it possible to check with LM that things have changed in 5.2?

For what it's worth (probably not much), on my i7 6700k, I see a much smoother flow with all cores enabled (HT on) although there are still some pauses. What I tried was using Process Lasso to allocate only the real cores 0,2,4 and 6 to P3d, and all the other main programs, FSUIPC, AS etc.to 1,3,5 and 7 but it ended up with P3D stuttering more than ever.

What I found the best for me was P3D on all cores and leave the others on the alternate cores. Unlimited in the sim, RTSS to one half refresh rate (of 60) and no further limiting necessary. Vsync and TB make no discernable difference.

Incidentally, as a test I switched in flight to full screen and immediately got a DXGI error, freezing the display.

1 hour ago, Wise87 said:

I thought if you have Hyperthreading off in bios then you don’t need to create AffinityMask? 

Generally true, although I do know a few people running 10-14 core CPUs that still use an affinity mask to reserve a couple of cores for ancillary processes.

Mine is as good as always, smooth as silk, didn't even notice the "downgrade" to a Laptop:

1 hour ago, Ray Proudfoot said:

, is it possible to check with LM that things have changed in 5.2?

I'd rather not, and I don't really see the point. They are very busy and this is a minor detail within a mass of changes from 5.1. to 5.2 and they very probably didn't deliberately arrange things for two such threads to get onto successive CPU IDs, real or otherwise.  It may just be a coincidence of timing, and, from that perspective, the problem may not occur as it does on yours on everyone else's systems. Take Ian's post just after yours as example:

1 hour ago, IanHarrison said:

For what it's worth (probably not much), on my i7 6700k, I see a much smoother flow with all cores enabled (HT on) although there are still some pauses.

and Nuno's:

26 minutes ago, Nuno Pinto said:

Mine is as good as always, smooth as silk, didn't even notice the "downgrade" to a Laptop:

Pete

 

1 hour ago, Pete Dowson said:

I'd rather not, and I don't really see the point. They are very busy and this is a minor detail within a mass of changes from 5.1. to 5.2 and they very probably didn't deliberately arrange things for two such threads to get onto successive CPU IDs, real or otherwise.  It may just be a coincidence of timing, and, from that perspective, the problem may not occur as it does on yours on everyone else's systems. Take Ian's post just after yours as example:

Understood thanks Pete. I’ll await the hot fix and see how things change.

I’m pretty certain I’ve run P3D v4 and v5 direct from the shortcut before and if the AM wasn’t set in the cfg then all cores would be used by default. But not with the problems I’ve had with 5.2.

3 hours ago, Wise87 said:

I thought if you have Hyperthreading off in bios then you don’t need to create AffinityMask? 

If you have multiple addons like a weather addon you might want it to run on its own core.

So without HT enabled you can also benefit from an AM.

With my 14 core processor I do not use HT but I do use an AM.

Edited June 19, 20214 yr by GSalden

1 hour ago, Ray Proudfoot said:

I’m pretty certain I’ve run P3D v4 and v5 direct from the shortcut before and if the AM wasn’t set in the cfg then all cores would be used by default. But not with the problems I’ve had with 5.2.

Agreed. That's why I suggested it was just a change in thread scheduling and timings in version 5.2 which affected your system, but not everyone's, and only if your P3D was using both threads in a core.

I of course agreed it was a change from 5.1 to 5.2. no one is disputing that!

Pete

 

Edited June 19, 20214 yr by Pete Dowson

Do you calculate AM w/ or w/ out HT enable?

How do you decide to enable or disable HT?

Can someone please suggest a good AM calculator.   There are so many options/opinions doing a google search.

Thanks. 

@Dreamflight767, in my case the PC was delivered with HT enabled.

If it’s enabled then for each physical core there are two virtual ones.

You enter a binary set of numbers into a calculator and the Decimal value shown is the value you enter into P3D.cfg in AffinityMask.

So, for example I have a six core i7-8086K. I want only one virtual processor to be enabled for each physical one. To calculate this use binary where 0=off and 1=on.

01 01 01 01 01 01

Open the Windows calculator in Programmer mode. Choose the Bin option. Enter the values above and press Decimal. It will show 1365. That’s the value you enter in Prepar3d.cfg

[JOBSCHEDULER]

AffinityMask=1365

But if HT is off and you still want to enter a value type 111111 and the Decimal value is 63.

For an eight core with HT off it would be 11111111 which equates to 255. With HT on it would be 0101010101010101 = 21845.

Hope that helps.

Ray thanks for all your efforts. I tried various Affinity Masks, including the one that worked for you. Unfortunately, none of them worked for me.

 

I did find a fix that worked. The problem for me was a combination of how I limit frame rates and the RXP GTN750.

 

Starting with P3Dv5.1, I set the frame rate limiter to 120 in the sim and set a max frame rate of 35 in NCP (most of you would probably use 30, but 35 works great for me with G-sync). With HT on, LP0 never hit 100%. However, with v5.2 this did not seem to work. I realized that all the aircraft that I used to test v5.2 had the RXP GTN750 installed. This seemed to be causing the 100% utilization on LP0 even with my method for limiting frame rates. The recent RXP GTN750 update did not fix the problem. So I uninstalled every trace if the GTN750 and did a clean install of the GTN750. That fixed the problem and I’m basically back to where I was on V5.1 with LP0 utilization.

 

So now with HT on, in sim frame rate limited to 120 and max frame rate of 35 in NCP:

● With EA off, LP0 utilization is between 65% and 85%.

● With EA on using legacy clouds LP0 is between 80% and 95%.

 

Everybody’s setup is so different, I’m not sure how helpful this is, but it worked great for me. LP0 never hits 100%. However, the other LPs do have higher utilization rates than v5.1. Not sure if this is better multicore utilization or just higher loads compared to v5.1.

 

The sim for me is now super smooth with no stutters or micro stutters. I love using EA with legacy clouds.

 

 

@DonMuskopf, I’m surprised you’ve set a limiter of 120. Why not use unlimited. It’s known that setting anything other that that degrades performance. Maybe G-Sync makes a difference.

Anyway, it seems there are no hard and fast rules with v5.2 so I’m pleased you’ve got your sim working to your satisfaction.

Hi All,

The issue of AM and various combinations has been around for a long time. Whilst setting the combination of LP being used is one thing, it always seems another to confirm how many should I be using?
 

Some people say they get better results by using all but the first core, others say all cores, some say use only half the cores. From my reading of Rays solution it seems he has set his to use six cores of his 12 8086k threads whilst leaving HT on in the bios. I recall trying same with my last 8086k and it resulted in stutters. Others then suggested to use five cores and leave the first one for Windows. 
 

I guess different solutions for different systems