Jump to content
Sign in to follow this  
Arismac

Affinity mask setting?

Recommended Posts

Basically, AM is worthless in P3d2. No shock there. Also, I undid the block on core 0 and that did nothing either good or bad to performance.

Share this post


Link to post

As I said in another post, P3D2 seems can only use three cores. When I used AM=15, I saw core 0 goes 100% and core 1-3 went down to 60-70%, so I still ended up using 75% of the total CPU. Only when P3D2 was starting a flight I saw all cores maxed out. Overall I saw no benefits of having AM=15 so I removed the AM in CFG file to let P3D2 runs on core 1-3 only.

 

This appears to be consistent with what LM said that they optimized P3D2 to run three threads, each per core.


7950X3D / 32GB / RTX4090 / HP Reverb G2 / Win11

Share this post


Link to post

Actually, they said that P3d2 will use as many cores as you have. If you have more than 4 cores, it will leave core 0 for use by the OS and other apps. I have 12 physical cores and P3d2 uses 11 of them by default. If I force it to also use core 0, it has no impact on performance one way or the other.

Share this post


Link to post

that could be true, but still when I set AM=15, I can max out core 0 but the rest of the three cores don't pick up any extra load. By default, P3D2 can max out all three cores 1-3. So it appears to me that although P3D2 can use many cores, there is still one core that works the hardest and becomes limiting when it gets maxed out, kind of defeating the purpose of having more than three cores running...


7950X3D / 32GB / RTX4090 / HP Reverb G2 / Win11

Share this post


Link to post

 I have 12 physical cores

 

Do you have a Opteron in your flight sim rig? 

 

Edit: Just saw your specs.. Xeon.. Same difference.. Lucky you! :)


ASUS ROG STRIX Z390-E GAMING / i9-9900k @ 4.7 all cores w/ NOCTUA NH-D15S / 2080ti / 32GB G.Skill 3200 RIPJAWS / 1TB Evo SSD / 500GB Evo SSD /  2x 3TB HDD / CORSAIR CRYSTAL 570X / IPSG 850W 80+ PLATINUM / Dual 4k Monitors 

Share this post


Link to post

that could be true, but still when I set AM=15, I can max out core 0 but the rest of the three cores don't pick up any extra load. By default, P3D2 can max out all three cores 1-3. So it appears to me that although P3D2 can use many cores, there is still one core that works the hardest and becomes limiting when it gets maxed out, kind of defeating the purpose of having more than three cores running...

 

 

I was coming to post just this, I see exactly the same behavior after testing both ways for a day or so. I really tried to do it LM's way, to see if they were right, and also to have tested thoroughly myself in case they were wrong.

 

Without an AM set, the primary core will sit at 100% utilization, This translates into behavior no different than with FSX.

 

So for me anyway, AM is just as much a requirement as it ever was. I think some guy named Dave or Dexter or something said the same 2 days ago   :P


Regards,

Brian Doney

Share this post


Link to post

Agree that there is something wonky with the AffinityMask.

 

For me, it's easily reproducible. Start in the default flight situation with the F22 on the runway. Hit the throttle, take off, and fly a pattern around the airport. If I don't add the AffinityMask setting in the config file, the textures take a while to load. They are a bit of a blurry mess.

 

If I add that setting, the textures are perfectly sharp no matter how fast or crazy I fly ("Maverick!"). Even switching views won't cause blurry textures. It's about 100x better than FSX for me.

 

It's not placebo. It really is night and day. I went through the comparison about 10 times. Of course, it's entirely possible it's an oddity specific to my system config.

Share this post


Link to post

Do you have a Opteron in your flight sim rig? 

 

Edit: Just saw your specs.. Xeon.. Same difference.. Lucky you! :)

The computer was original purchased for video editing, but I now use it for routine stuff and flight simming. P3d 1.4 would use 5 or 6 cores, but P3d2 uses them all, as long as you use Process Explorer to let it use core 0.

Share this post


Link to post

Agree that there is something wonky with the AffinityMask.

 

For me, it's easily reproducible. Start in the default flight situation with the F22 on the runway. Hit the throttle, take off, and fly a pattern around the airport. If I don't add the AffinityMask setting in the config file, the textures take a while to load. They are a bit of a blurry mess.

 

If I add that setting, the textures are perfectly sharp no matter how fast or crazy I fly ("Maverick!"). Even switching views won't cause blurry textures. It's about 100x better than FSX for me.

 

It's not placebo. It really is night and day. I went through the comparison about 10 times. Of course, it's entirely possible it's an oddity specific to my system config.

 

 

Same here on an I7 920 with HT disabled. Night and day. Flying or even worse slewing without the affinity mask set to 14 always ended in a blurry mess. With the affinity mask set, textures remain crisp whatever I do.


KInd regards

Jean-Paul

I7 8700K / Fractal Design Celsius S24 watercooling / ASRock Z370 Extreme4 motherboard / Corsair 32GB 3200mhz DDR4 / INNO3D iChiLL GeForce GTX 1080 Ti X3 / Samsung SSD 960 EVO M.2 PCIe NVMe 500GB / Seasonic-SSR-850FX power supply / Fractal Design Define R5 Black case / AOC Q3279VWF 32″ 2560x1440 monitor / Benq GL2450 24″ 1920x1080 monitor / Track-IR 4

Share this post


Link to post

If you want to see why, have a look at your core utilization without AM set.

 

Having a core completely saturated, like the primary core will be without an AM (14 or 84) set, is definitely not a good thing. Any threads that are on the core will be contending for time, and you will without a doubt feel/see that while the simulation is running.

 

This is really no different than it was with FSX.


Regards,

Brian Doney

Share this post


Link to post

I want to happily report here that AM=14 did wonders to solve my texture loading problem! It's so good it's almost unbelievable. I'm really surprised by this since without adding AM the P3D2 already runs on core1-3, so adding AM=14 seems to be redundant.

 

However, things are indeed different when I actually added AM=14 into the CFG file. Under my near "maxed-out" settings, in a very autogen heavy area like San Francisco, without any AM core1 is constantly maxed at 100%, and core 2 + core 3 each runs close to 90%-100%. And I easily get slow or even stuck on loading ground textures (i.e. blurry!).

 

Setting AM=15 doesn't help the texture loading problem at all. Now core 0 runs a constant 100% and the rest three cores each runs around 60%. And I remember that Windows uses core 0 to so maxing out core 0 is a bad idea.

 

Now, with AM=14, what I have got appears to be the best distribution of core-loading: core 1 at 100%, core 2, 3 and 0 each at like 60%, 50% and 40%. I don't know why core 0 gets loaded under AM=14, but by all means my blurry ground texture problem is now completely gone! This is exactly the same results Jimmy reported couple posts above.

 

When I switch views I still can get very blurry ground textures, but instead of waiting minutes or forever for P3D2 to reload them now P3D2 reloads them in seconds or even less. I'm so happy about this.. Life with P3D2 keeps getting better!


7950X3D / 32GB / RTX4090 / HP Reverb G2 / Win11

Share this post


Link to post

Setting AM=14 makes a significant difference for me. I am very curious to know why since this is supposedly the default. Its as if PD3 forgets it should be doing AM=14 unless explicitly set in the config file. Any ideas?

Share this post


Link to post

I saw no performance difference with AF settings and saw zero difference monitoring the cores enabled or disabled. I run 2700K with HT enabled so AF=84 is my setting. P3D seems to spread the load across three cores leaving the first open by default for me making this tweak redundant. It's odd that some are noticing otherwise.   

 

I have not tried AF=252 which should use the virtual cores. I'm interested to see if this makes a difference.


Intel i7 10700K | Asus Maximus XII Hero | Asus TUF RTX 3090 | 32GB HyperX Fury 3200 DDR4 | 1TB Samsung M.2 (W11) | 2TB Samsung M.2 (MSFS2020) | Arctic Liquid Freezer II 280mm AIO | 43" Samsung Q90B | 27" Asus Monitor

Share this post


Link to post

I just got P3D installed and I have never tweaked FSX, so I am asking this question from a base of no tweaking knowledge.  I am looking in the Prepar3D file within the following path:

c:/Users/Owner/AppData/Roaming/Lockheed Martin/Prepar3d v2

 

I am unable to find anything stating:

[JOBSCHEDULER]
AffinityMask=n

 

Can someone please assist in helping me locate this.  Thanks.


spacer.png

REX AccuSeason Developer

REX Simulations

Share this post


Link to post

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  
  • Tom Allensworth,
    Founder of AVSIM Online


  • Flight Simulation's Premier Resource!

    AVSIM is a free service to the flight simulation community. AVSIM is staffed completely by volunteers and all funds donated to AVSIM go directly back to supporting the community. Your donation here helps to pay our bandwidth costs, emergency funding, and other general costs that crop up from time to time. Thank you for your support!

    Click here for more information and to see all donations year to date.
×
×
  • Create New...