If they don't manage core affinity themselves, start them with a .bat file

 

Hi Carl,

 

May I direct your attention to this excellent site. In particular, and with reference to Steve's suggestion, this informative page:

 

http://www.codelegend.com/forums/viewtopic.php?f=2&t=632

 

Remember, that while such guidance is based on established proven principles there can be no substitute for your preparedness to spend some time experimenting with different values of Affinity Mask coupled with optimising settings within the sim as determined by the capabilities of your hardware. This, of course, assumes you're intention is to run other Apps alongside the sim. Try not to be unrealistic as a great experience can still be achieved with a relatively modest setup.

 

Regards,

Mike

Much obliged gentlemen... I shall experiment with =252 and =244 and ensure that my other program is running on LPs 1.

 

Ta!

Always give your other apps at least two LPs if available. You can let them use LP0 and LP1 with your sim AM=244 or 252.

So with an Affinity Mask of 255 for a 4 core processor with HT ON means that P3D will use ALL your cores. Is this what the default setting for P3D is when you have no Affinity Mask entries in your Prepar3d.cfg file?

Yes, if you don't put in an AM and you have 8 LPs no AM=0=255=11111111 P3D counts the available LPs and automatically makes a task on each LP without checking for HT. This would result in over-use of the L3 cache some speak of (see Robs P3D guide). Think of the first four tasks created by the sim one per LP doing the most work, the other four go to help speed up the collection of scenery data. Remember that a four core+HT is still four cores so the first 4 LPs are only the first two cores. That's why the AM=85=01,01,01,01 and AM=253=11,11,11,01 are better since they allow P3D to create only one task on one LP of the first core.

Hi Steve

Have HT on nowdays on the 6700k AM116 works really great only 7-8C hotter then HT off.

Run up to 4.9ghz with HT on now

 

But on the 5960x i prefer HT off like before.

Yes, with hyperthreading CPUs each core has a chunk of extra circuitry to store and retrieve the thread context without latency. Obviously this adds heat into the system, especially with more cores, but it's doing more work to switch threads with no latency so the frequency can come down. Also the more cores you've got doubling up with HT the more problems you get if there's some kind of process doubling up on tasks.

I just spotted your thread, good stuff and good research.. this after I had just posted an issue (along with my settings) i'm having related to AM and blurries.

 

Short version is that I run a hex core i7-4930k at 4.4 from 3.4 (HT on, unlimited frames).. with 980ti 4gb SC+.. i use fsmark07 with ftx+gex+utx as a baseline tester (maybe this is the issue, its very heavy hitting)..

If i turn OFF AM or set to 4095 (same thing i think).. i get blurries after a minute or so.. hit pause the autogen pops back in.. if i use 4092, my avg frame rate over 120sec jumps from 22 to 29 fps with moderately high settings with some shadows etc .. if i lower the graphical settings, blurries do NOT reduce.. lowering / raising lod radius doesnt help either.  I usually have frames set to unlimited, i havent tried locking at 30 yet, i'm sure this would kill the avg framerate on the test though, but maybe smoother.

 

 

I'm at a loss here.. i mostly run off a laptop for things like ASN, but figured keeping 1 or 2 logical cores free was a good idea, (4092?) not sure why this value or various other values i've tried causes blurries.. cpu max for the p3d exe seems to max at 55% while the gpu maxes at 95% but ram out of 4gb video at 2GB or so.  Other values that result in blurries include 2560, 4085, 1364 was only slightly better and 2560 i think also wasnt so great blurry wise... fps wise 4092, 1364 being king here on the 120sec test.  Seems 4092 is the last two threads free and 1023 would be the first two, havent tried 1023 yet, though not sure this would make a difference.

 

One thing i noticed, the prepar3d.exe if you right click in task manager and view affinity on it.. ALWAYS seems to have all the cores checked off.. is the setting in prepar3d transparent to the OS in that you wont see certain cores unchecked in task manager regardless of AM.. i really cant recall?  Either way, no matter how you cut it, looking at the fraps viewer for the 120sec tests, no matter which one.. are certainly not that smooth, not using this hard hitting flight as a test, certainly not throughout the middle part.

OK let's have a look. i7-4930k is with HT 6 cores 12 LPs.

 

With HT on and no AM=0=4095=11,11,11,11,11,11

With HT off and no AM=0=63=111111

 

So with HT off no AM would work quite well, but with HT enabled it would not work so well.

 

 

I would first try what I posted in #516 for the six core:

 

"For the six core and P3D I set P3D with an AM=1365=01,01,01,01,01,01 and I set all addons to LPs 9 & 11 = 2560 Dec = A00 Hex = 10,10,00,00,00,00 Bin"

 

You should see the allocated LPs as checked CPUs in Task Manager details, Set Affinity, you will always see all enabled with FSX.

OK let's have a look. i7-4930k is with HT 6 cores 12 LPs.

 

With HT on and no AM=0=4095=11,11,11,11,11,11

With HT off and no AM=0=63=111111

 

So with HT off no AM would work quite well, but with HT enabled it would not work so well.

 

 

I would first try what I posted in #516 for the six core:

 

"For the six core and P3D I set P3D with an AM=1365=01,01,01,01,01,01 and I set all addons to LPs 9 & 11 = 2560 Dec = A00 Hex = 10,10,00,00,00,00 Bin"

 

You should see the allocated LPs as checked CPUs in Task Manager details, Set Affinity, you will always see all enabled with FSX.

 

Thanks..

 

In my case i have HT on.. so you are suggesting to try AM 1365 I take it? Which is really just using 6 LP's of the 12.. when you say you set addons to LPs 9,11, how do you mean exactly... two different AM's for different cases or something else?  I guess limiting the cores further would help on VAS usage?

 

I do now see unchecked LP's in task manager, before i didnt, maybe i wasnt letting it load fully first.

 

EDIT: tested 1365, i think this wins, though if you view the frametime in fraps viewer its not flatline and low MS like it could be, but then again this is fsmark07/ftx/ksea area in the big bird.

Avg time 41.1, 1% time 66.3, 0.1% time 108

The rule I recommend for addon exe apps is to give them at least two LPs, so LPs 9 and 11 are the sister LPs to the ones allocated to P3D on cores 4 and 5, This way we leverage HT on those last two cores. Sharing P3D background thread cores with other tasks is OK when we don't have so many cores, but keep apps away from the first and second P3D jobs on cores 0 and 1 if you've got enough cores. P3D has four main jobs, even if only one LP is allocated, These jobs split out over the first four LPs, the jobs 3 and 4 can be used on shared cores with less worry.

Take a look at my System in the signature. Now i have a 24' Gsync monitor.

 

I have very good performance with Gsync and default aircraft, but with PMDG 777 i have microstutters with all settings i have tested. I down the sliders, put high, tested all. Fresh cfg. No NI only for SGSS. In Aerosoft airport and PMDG i have about 40 Fos on ground. With default aircraft and scenery i have about 100 and very smooth sim.

 

No AM. HT off.

 

Can you help to identify my cause of microstuttering? It's a good performance sim but with micro stutters.

Take a look at my System in the signature. Now i have a 24' Gsync monitor.

 

I have very good performance with Gsync and default aircraft, but with PMDG 777 i have microstutters with all settings i have tested. I down the sliders, put high, tested all. Fresh cfg. No NI only for SGSS. In Aerosoft airport and PMDG i have about 40 Fos on ground. With default aircraft and scenery i have about 100 and very smooth sim.

 

No AM. HT off.

 

Can you help to identify my cause of microstuttering? It's a good performance sim but with micro stutters.

 

G-sync, isn't great in the 30-40fps i find, it works great 60-100 and okay 40-60, 

 

I'd reckon, with a 2600K you'll struggle to get the frames you need to make 777 shine efficienty on g-sync

Given that 1365 has worked well with my i7-4930k hex.. what have others found to be a good value for the i7-6700k?    (the search option for this thread seems to be missing, at least in my browser?)  edit:  i think its 252 based on the calculator in windows.. is this a good one, have others found it to be the best?  

 

edit2: NO actually, 1365 is 11 cores alternating, not 12.. not sure how/why that one worked best on the 12 core.. so i guess the equivalent 8 core might be 85 (7 cores alternating), which is in perfect sync with the OP first post and findings.. ?

Given that 1365 has worked well with my i7-4930k hex.. what have others found to be a good value for the i7-6700k?    (the search option for this thread seems to be missing, at least in my browser?)  edit:  i think its 252 based on the calculator in windows.. is this a good one, have others found it to be the best?  

 

edit2: NO actually, 1365 is 11 cores alternating, not 12.. not sure how/why that one worked best on the 12 core.. so i guess the equivalent 8 core might be 85 (7 cores alternating), which is in perfect sync with the OP first post and findings.. ?

 

Since it's a quad-core with hyperthreading, it'll probably be the same as my 2600K setting, which is AM=84.