Affinity Mask: An Observation

[Jimm 437]

I recently bit the bullet, again, reinstalling everything.  I won't get into specifics but recent OOMs I experienced made me start an investigation.  After reinstalling a basic setup, my tubeliners, ORBX FTX Global, ASN, REX, with a few 3rd party airports, I looked into possibly making some changes to my cfg file and even my nvidia settings.  One of the changes I made was incorporating an Affinity Mask setting.  I went through a tut here at AVSIM to determine the appropriate number and plugged it in.  I left the rest of the cfg file alone, cloning other settings with a previously saved version I had before the reinstall.  I made a couple of changes to my nvidia display, via the control panel and went ahead and flew a route.

 

My route was rather short, EGKK to EGPF, with an Airbus A318 from Aerosoft.  About half way through my flight I noticed that the ground scenery over England suddenly started to look blurred.  Not just a slight blur, but as if I was going to be flying over desert.  I also noticed that my clouds were not refreshing properly, leaving large gaps between refresh, and even then, the clouds were looking off.  I took at the ground below, and I noticed that the once beautiful ground shadows looked like tetris blocks.  Before approach, at about 4000 feet, the ground started to look better and so did the clouds, but from that point to touchdown, all of the surrounding ground textures were very blurry.  With the exception of the airport scenery, which looked fine, everything else look bad.  I completed the flight without any issue.

 

Afterwards, I thought about what would have caused this issue, and realized that the AM setting I placed in cfg could be the cause.  I went ahead and commented out the AM line in my cfg and later on, performed a new flight.  This time, my flight took me from EGKK to LOWW, a much longer flight with a slightly different aircraft.  I had OpenLC Europe installed and active within FTX Central as well.  After a 2hr and 15 min flight, the entire flight was beyond perfect.  I had no issue with my weather, clouds (saw some great thunderstorms with tops above FL400.  As for the scenery, it was clean and clear, no blurries at all.

 

With this change, I am convinced that AM doesn't always work or rather, is needed.  I never used it before for v3, up until recently, which had the bad effects from the flight mentioned initially.  Changing things back to no AM has made a difference and I don't really think I need it anymore.  All of this was just an observation for those who may consider using it.  I guess you need to determine of any issues you have with P3D warrant it's use.

 

-Jim

[pmb 5,137]

Here come the two critical questrions, Jim: Which processor do you use (i.e. # of physical/logical cores)? Do you have Hyperthreading in the BIOS on or off?

 

Kind regards, Michael

[Jimm 437]

I have an intel i7-4790K, oc'd to 4.5ghz.  I never ever ever touched hyperthreading so it would be a yes, I use it.

 

I have a feeling your answer will be, "well sure, with your processor, you never needed to use AM", and if that's the case, I'll be happy with that response and continue on with great, stable scenery and wonderfully beautiful puffy clouds.

 

-Jim

[pmb 5,137]

No, The 4790 has 4 cores and 8 threads, that's the same as mine (although mine is weaker). If you have HT off, most would agree you should not use any AM with a 4 core processor. This is what I use at present.

 

If you have HT on (check in the BIOS, or the Task Manager/Resouce Monitor should show you the # of threads) things get more complicated, but usually it's suggested to use an AM in this case. I expect Steve Waite will jump in soon and tell you what to do in this case  :smile: Until then, you can read his page http://www.codelegend.com/forums/viewtopic.php?f=2&t=532

 

 

Kind regards, Michael

[Jimm 437]

No, The 4790 has 4 cores and 8 threads, that's the same as mine (although mine is weaker). If you have HT off, most would agree you should not use any AM with a 4 core processor. This is what I use at present.

 

If you have HT on (check in the BIOS, or the Task Manager/Resouce Monitor should show you the # of threads) things get more complicated, but usually it's suggested to use an AM in this case. I expect Steve Waite will jump in soon and tell you what to do in this case  :smile: Until then, you can read his page http://www.codelegend.com/forums/viewtopic.php?f=2&t=532

 

 

Kind regards, Michael

Well then this begs the question as to why I would need it if everything is running fine?

 

-Jim

[DaveCT2003 1,820]

It's not just the number of cores... it's the processor architecture. The 4770K and above processors seem to function best without AM as they manage processing better.  I believe there are a few threads on this.

 

My very best to all.

[neucoas 82]

"About half way through my flight I noticed that the ground scenery over England suddenly started to look blurred.  Not just a slight blur, but as if I was going to be flying over desert."

 

Same here, with AF=14 (i5 3470)

 

In the middle of the flight, i changed the AF via task manager, and all the blurries gone.

[glider1 90]

 

 

In the middle of the flight, i changed the AF via task manager, and all the blurries gone.

 

With blurries, we think in terms of ongoing maintainable processor throughput as it infills and backfills the terrain. With P3D, we no longer think in terms of frame rates, more about blurries which are the way of knowing that the system is overloaded. P3D has tried to make it so that we can complete a flight with less compromise on framerates and more compromise on terrain rendition (but not at the critical airport destination where the terrain needs to appear so that we can land). If there aren't enough processing resources, this is a better approach than compromising frames. It is all about throughput of processing. If you change the AF mid flight, I think you can temporary cause processing to complete throughput of rendition, but later it will fall behind again because the underlying cause is not addressed. Affinity mask is able to influence (but not control) the job-scheduling load outside of the simulator and that is why it is helpful when addons are running as well as the simulator.

[GSalden 4,652]

It's not just the number of cores... it's the processor architecture. The 4770K and above processors seem to function best without AM as they manage processing better. I believe there are a few threads on this.

 

My very best to all.

This statement is totally incorrect.

 

There are enough threads with enough info on HT and AM that prove that using HT with a correct AM gives the best performance and with the smoothest experience...

 

( my cpu : 5820K@ 4.3 Ghz , HT on and AM=340 , addons outside P3D on cores 0,1,10 and 11 )

[jason99vmi 157]

Jim- I have the same exact processor but not overclocked above 4.0.    I've tried a number of AM settings as well as the FTFF tweak and both have provided no advantage.  And in fact when I have the AM tweak in the cfg it has produced blurred terrain.  FTFF produced slower loading textures when in the cfg. 

 

While I have read many of SteveW's posts and his fantastic work with this setting, I have yet to gain advantage from AM. 

 

But then again maybe I'm not adjusting it quite right. 

 

Pretty happy with the performance now.  Only have trouble in real heavy cloud coverage.  And that's cause my GPU is a tad on the old side.  GTX 760. 

[Jimm 437]

Jim- I have the same exact processor but not overclocked above 4.0.    I've tried a number of AM settings as well as the FTFF tweak and both have provided no advantage.  And in fact when I have the AM tweak in the cfg it has produced blurred terrain.  FTFF produced slower loading textures when in the cfg. 

 

While I have read many of SteveW's posts and his fantastic work with this setting, I have yet to gain advantage from AM. 

 

But then again maybe I'm not adjusting it quite right. 

 

Pretty happy with the performance now.  Only have trouble in real heavy cloud coverage.  And that's cause my GPU is a tad on the old side.  GTX 760. 

Jason, thanks for your input.  I was beginning to think I was the only one who didn't benefit from using AM.  Since i started to use P3D v3.2, I recognized the huge improvement to fps and overall performance.  I only recently read some posts concerning AM and it's potential benefits, thinking perhaps I might gain some more performance, but like you, it got worse.  As you say, we may not be setting it correctly, but to be honest, if our sim works fine and to our liking, I guess we can do without.  Only one potential benefit I could glean from Michael's link above was heat.  Spanning the cores properly, there may be a benefit of reduced heat, but again, I run my sim on a laptop and it seems to expel the heat as efficiently as it can.   Since my typical length of flights span a little over 2 hours at a time (which is about the norm for what i have time for), I cannot complain one bit about how everything comes together.  I got my cloud issue straight with REX and ASN and my settings in P3D are just right.  I only run FTX Global nowadays, since I fly tubeliners and I don't receive any added benefit of having ORBX regions (or even Vector for that matter) installed.  As long as my sim doesn't look like a blurry mess, I'm happy.

 

-Jim

[G-YMML1 580]

I think that true benefit of using AM becomes distinctive when you're utilizing the external applications such as ASN, FSC, RC4, PATC...too many to mention. "Naked" P3D does not need AM. 

[Midnight Music 252]

I think the whole AM thing needs to be revisited but only about version 3.2

 

In earlier versions of P3D I always had an AM setting in my CFG per the suggestions made on this forum, and it did help, but somehow with V3.2 it doesn't help anymore. Something has changed. I removed the AM settings and the sim works much better for me. Doesn't no entry in the CFG still default to AM=14? I only use one tweak FFTF 0.10. My rig is basically an i7 4770 oc 4.3 with a 980ti. I have not touched HT. It runs very smoothly with very few blurries. I still use NVI at 4xSSGA to help the visuals. Again, it is fine, no slow down. That being said, I don't run my sliders all the way to the right. I have found decent balances between visuals and performance.

[sascha 314]

There are enough threads with enough info on HT and AM that prove that using HT with a correct AM gives the best performance and with the smoothest experience...

 

Well ... I guess the prize question then is: What is the correct AM?

 

Tweaking FSX and P3D seems to require really specialist knowledge these days. I'll jump in when I have a really high-end new system.

[virtualstuff 750]

This statement is totally incorrect.

 

There are enough threads with enough info on HT and AM that prove that using HT with a correct AM gives the best performance and with the smoothest experience...

 

( my cpu : 5820K@ 4.3 Ghz , HT on and AM=340 , addons outside P3D on cores 0,1,10 and 11 )

 

Correct I'm here with Gerard ;-)