A fresh debate on Affinity Mask and modern quad core CPU's

[RaptyrOne 1,404]

There are many posts on these and other forums discussing AffinityMask. Been thrashed to death, almost. Until now I have taken note of them but never incorporated them into my FSX.cfg, mainly because there are way too many opinions on what is right and whether it makes for a better experience or a worse experience in the sim. "If in doubt, pull out" is what I say :-) pretty sure many opinions are placebo.

 

A recent in-flight 8 minute freezing problem seems to have been fixed by using the AffinityMask setting however, after it was suggested in another forum here on Avsim. Still early days but no freezes since going with a setting of 252.

 

Hyper Threading on or off? Why turn it off unless you are pushing your CPU to its overclocking and temperature limit? Why restrict your expensive processor to only 4 cores just because FSX is unable to make full (any?) use of it? It is not like your sim will run slower with HT off? But the rest of your computing on that computer might. Either FSX can see the virtual cores or it can't. So I run with HT on....

 

Then comes the question, do you go with an AM setting that turns off just the first main core (255) or both the first core and it's virtual partner (252)? Surely it matters as we are reserving this first core for Windows and it's processes and Windows CAN see the virtual core even if FSX can't?

 

Why is it suggested that 84 be used with HT on? Does this figure not totally ignore the virtual cores? Akin to turning HT off as far as the simulator is concerned? If FSX does not see virtual cores and Windows cannot make use of these virtual cores while the sim is running, then surely 84 and 252 are the exact same result?

 

I know the suggestion to 'experiment and see what works for you' but I don't like to experiment, I like to fly :-) Plus I feel better not second guessing myself on which setting "might" be better than the next - placebo improvements or otherwise can easily get the better of all of us from time to time.

[charliearon 3,023]

Try to keep in mind what works for one may be instant death to another.  Minor experimentation,

 

if done in small steps with plenty of documentation,  could yield great rewards.

[newtie 533]

A small amount of searching will answer almost all of your questions.

 

As you mention in your first paragraph, this topic has been thrashed to death.

 

Cheers,

Mark

[Bert Pieke 7,584]

There are three schools of thought on this.. and that is why you see endless debates..

 

Here is an attempt to describe the three theories:

 

1.  FSX does not support HT and runs better if only one thread per core is in use, and if FSX does not run on the Windows core,  so either turn off HT in the BIOS and use AM=14 or simulate this with HT turned on which leads to AM=84

 

2. Even though FSX does not support HT, Windows does - so why not give Windows lots of texture loading cores to schedule threads on, the more the better!  This leads to HT=on and AM=254 or 252 etc

 

3. Ignore FSX preferences, Windows 7 is smart enough to schedule work efficiently,  and I paid for (four) eight cores, so lets put them all to work, which leads to AM = 15 or 255.

[Cai Zicheng 171]

 

 

3. Ignore FSX preferences, Windows 7 is smart enough to schedule work efficiently,  and I payed for (four) eight cores, so lets put them all to work, which leads to AM = 15 or 255.

 

I think this leads to micro-stuttering.

[Bert Pieke 7,584]

..and let the debate begin  :rolleyes:

[gfd 15]

..and let the debate begin  :rolleyes:

So very dry...so very good!...from a fellow Canadian

[SirStiggie 63]

..and let the debate begin  :rolleyes:

 

lol.

 

Throw in other applications you may be running (weather engine, FS INN/ Sqawkbox, ACARS, etc) into the mix as well for those not fortunate enough to have a network for simming.

[RaptyrOne 1,404]

I think we should have a poll and see what everyone out here is using? :-)

 

... And I recon that 252 also leads to micro stuttering.

 

Is AM=15 not the same as no entry in the cfg at all?

[Cai Zicheng 171]

I think AM=84 works best for HT ON

[McLaren 42]

I have left it out completely! No need to clutter up the CFG file.....

[777 340]

I have left it out completely! No need to clutter up the CFG file.....

Exactly why fill the cfg. With these "bloatware" tweaks not knowing what they are doing in FSX, then complain when things go wrong, all Placebo to me.

I can add to the debate that HT on lead to stutters for me, may work wonders for others...

[RaptyrOne 1,404]

Agree with you McLaren and 777.

 

I am not using these tweaks: Affinity Mask,  the Bufferpools tweak, Fibre Frame Time Fraction etc etc... - because they are at best placebo and at worst create other issues. HOWEVER my problem actually appears to be solved by applying the AM tweak. (Freezing up in flight for a couple minutes at random.)

 

Of course, it may well be that another problem is causing this problem and now I am fixing the secondary problem which might lead to more problems.......

[SolRayz 392]

I really shouldn't encourage debate in this old topic that has been discussed ad nauseam for almost a decade, but AF, BP, and FFTF are hardly "bloatware" or placebo tweaks as was suggested. Plenty of verifiable evidence that these are quite effective.

[McLaren 42]

Agree with you McLaren and 777.

 

I am not using these tweaks: Affinity Mask,  the Bufferpools tweak, Fibre Frame Time Fraction etc etc... - because they are at best placebo and at worst create other issues. HOWEVER my problem actually appears to be solved by applying the AM tweak. (Freezing up in flight for a couple minutes at random.)

 

Of course, it may well be that another problem is causing this problem and now I am fixing the secondary problem which might lead to more problems.......

 

Not sure what aircraft/situation you are experiencing this with but I had the same issue with the Majestic Dash8 and I thought it had to do with AM/Lack of AM setting. What it ended up being was FSUIPC autosave. 

 

 

I really shouldn't encourage debate in this old topic that has been discussed ad nauseam for almost a decade, but AF, BP, and FFTF are hardly "bloatware" or placebo tweaks as was suggested. Plenty of verifiable evidence that these are quite effective.

 

 

Is this the case with newer hardware? I have done a fair amount of testing with my rig (see specs on the left) and have found that my best experience comes from no tweaks in the CFG other than HighMem and DsiablePreLoad. I also have 2048 textures for FSDT airports and LOD=6.5 from an eye-candy standpoint.