P3D affinity mask?

[nicksort 8]

Hi,

 

also have an i7-4790K with HT=on.

 

I use AM = 253 (11111101) in P3D.cfg (just to mask the LP 1 of the first physical core - so the main thread can make full use of it)

 

Then I set the affinity mask for (almost) all other processes running in the background, to get them off the physical core 0 (they use cores 2-7). I use Process Lasso for that purpose.

 

This gives me a really fluid sim, because P3D can make full use if the first core without interruptions. The other cores are never at 100% and can serve all the other threads easily.

 

Thanks to Steve for pointing me in the right direction :smile:

Has anyone tried what Marc has posted, this is interesting, I will not be able to get to this until this weekend.

[SteveW 1,792]

On your dual core with HT enabled, AM=14 gives a whole core to the main thread maximising throughput for the main thread. AM=15 shares the core between the main thread and texture loading giving more texture bandwidth.

[SteveW 1,792]

On your dual core with HT enabled, AM=14 gives a whole core to the main thread maximising throughput for the main thread. AM=15 shares the core between the main thread and texture loading giving more texture bandwidth.

 

Should prove interesting. Remember though that Windows jobsheduler is pretty good at sorting things out efficiently. The only reason we use the AM masking that one LP is because the sim isn't up to full bore when the second thread starts up, and so gets dropped onto the same core if we don't help it onto the next core with the mask.

 

 

For proof we can go back to that image I posted earlier. Check out the top half again, around two thirds into the trace a scheduled app starts up. Jobsheduler keeps it off of the main thread core very effectively, since LP7 continues to do very little alongside LP6, and the sudden extra work gets distributed across the rest of the chip.

 

[boeingaviation 0]

Hi I know this is an old topic. But was wondering I have an i7-4790k which is quad core with 4 cores 4.4ghz with hyperthreading on.

 

Would an AM of 244 be suitable for my system. Just really confused as I tried to use this calculator:

 

http://www.gatwick-fsg.org.uk/affinitymask.aspx?SubMenuItem=hardware

 

I used the expert mode and selected Logical 0-4 as I have 4 cores & Thread 1-4.

 

It came back with AM mask of 2097 but I believe I've done something wrong as anotherember pointed out that value should be for a 6 Core CPU.

[npole 21]

Hi I know this is an old topic. But was wondering I have an i7-4790k which is quad core with 4 cores 4.4ghz with hyperthreading on.

 

Would an AM of 244 be suitable for my system. Just really confused as I tried to use this calculator:

 

http://www.gatwick-fsg.org.uk/affinitymask.aspx?SubMenuItem=hardware

 

I used the expert mode and selected Logical 0-4 as I have 4 cores & Thread 1-4.

 

It came back with AM mask of 2097 but I believe I've done something wrong as anotherember pointed out that value should be for a 6 Core CPU.

 

4 cores, all threads.. you need to select every thread from 0 to 3 (0,1,2,3 = 4 cores / threads), the mask is then: 255

 

...but if you want a suggestion, do not add any affinitymask at all, unless you need to do something special (ie: running external apps, like streaming software on different cores, etc.) because you could cause more harm than anything (it was useful back in time.. it's not anymore).

[boeingaviation 0]

Thank you for your help.

 

I put AM mask of 255 but that just selected all my cores and threads. Ihave manually unchecked Core 0&1 and AMD is running on all the rest.

 

 

I think I will remove the AM altogether after I finished my current flight and see how the sim performs.

 

My main reason for trying to set this up was to help remove blurry ground textures.

[npole 21]

Thank you for your help.

 

I put AM mask of 255 but that just selected all my cores and threads. Ihave manually unchecked Core 0&1 and AMD is running on all the rest.

 

 

I think I will remove the AM altogether after I finished my current flight and see how the sim performs.

 

My main reason for trying to set this up was to help remove blurry ground textures.

 

If you disable the first core (the first two threads) you gonna have issue with scenery loading with p3d 3.2.

I was doing the same because I wanted to free the "windows" core, since I needed some CPU for  the external apps and for the streaming, then i figured that all the trouble I had with the blurred scenery and the slow texture loading, was about that disabled core.

I'm not sure if it will be the same with the AMD, but if you have a CPU monitor, look at the usage.. you will notice that the first core is used almost 100%, and when you disable it, P3D is not capable of assigning the same tasks (at the same rate) to the other cores available, causing the issue above.

 

This is the reason of why I said: unless you have some specific needs (in example I use the affinity mask to disable the last core of my 6 cores, since I have the streaming apps running there) do not use it... it could cause more harm than anything with the 3.2.

[glider1 90]

 

 

If you disable the first core (the first two threads) you gonna have issue with scenery loading with p3d 3.2.

 

There is something in that theory. I tried something yesterday where I can get AM to work properly with scenery loading in 3.2, but it is experimental. Some people are using AM with radically extended FFTF's and that seems to be one approach. It would be nice to get some consensus on whether the problem is real or not.

[npole 21]

Just to add some details... i then tried to "compensate" the loading by increasing the FFTF above 0.33 (that is the default) .. with no significative advantage, if not the progressive loss of FPS, plus some other minor tweaks... but ended to nothing. So I decided to reactivate the first core and disable the last one instead.. it won't free up the common tasks, but I can use the affinity mask in those others apps to use the last core instead.

 

NOTE: I use orbx global + OpenLC Europe + Vector .. I don't know if it will be the same with the default scenery.

[boeingaviation 0]

Ok thanks for all those good replies.

 

I have disabled AM and am running on all cores and CPU usage hits 60% overall sometimes during flight.

 

Core 1 is now being used 100% before it wasn't and load for the rest of the game is shared across the other cores. Other cores are running about 40-50% usage where as core 1 is at 100%.

 

I will need to see what it like with the ground textures when it's daylight (current flight is a night flight).