FSX-MS affinitymask i7 7700k

[Dane Watson 38]

1 hour ago, SteveW said:

...often AMs amount to the same thing, for instance 170=10,10,10,10 and 85=01,01,01,01 or even 165=10,10,01,01 all work the same as far as the sim is concerned however we must remember with HT enabled configurations like 01,10 uses two cores but 00,11 uses only one core.

Thank you

[Hypofx 10]

Hi Stevie,

Tried few settings but a bit unclear- i have 6800K HT off what should be the AM? and is it worth to check with HT on ??

 

[GEKtheReaper 364]

@HypofxHi, it's realy easy to get your AM number right by yourselfe if you understand the "trick".

Intro:

You have a i7 CPU which has 6 Physical cores but can handle 12 threads (in addition to your 6 physical cores you have 6 logical cores also. So 6+6=12 Threads -> this is called Hyperthreading or HT).

In your Task Manager under performance you can select to show also your logical CPU cores and you should see 12 cores. If you don't see 12 cores then you have Hyperthreading turned OFF in BIOS (I don't think you did this and it's enableb by default).

The cores with HT anabled are numbered as follows:

0 - 1st physical core

1 - 2nd logical

2 - 3rd physical

3 - 4th logical core

4 - 5th physical core

5 - 6th logical core

6 - 7th physical core

7 - 8th logical core

8 - ....

So they alternate...

Now all this cores and threads can be enabled = 1 or disabled =0

The trick (e.g on a i7 4Cores / 8 Threads):

Open your calculator, select the programming view then BIN and enter 0 or 1 for the cores you want to enable / disable BUT in reverse order (normal order would be core 1-2-3-4-5-6-7-8 reverse would be 8-7-6-5-4-3-2-1).

Simple example:

a) If you want FSX to run on all 4 physical cores you will type in the calculator:

01010101 = Core 8 (logical) OFF, Core 7 (physical) ON, Core 6 (Logical) OFF...

Now read what the DEC number of your entry is displaying: I bet it is 85!

b) If you want to load ALL 8 cores the BIN entry will be:

11111111 = 255

If you turn off HT in BIOS (or have a CPU which has no HT e.g. i5 CPU) then you will only have 4 physical cores.

Example if you want to use ALL 4 cores your BIN entry will be:

1111 = 15

You will see the effects if you monitor the CPU load from Task Manager :).

 

Now the bad thing:

FSX is rather old and can't see your Logical cores. You can still set it to run on them (they will also be shown in task manager as beeing in use) but you will have stutters in the sim (let's call it a fake view). So the best thing is to load only your Physical cores.

System dependant AM setting:

Depending on your system load you can set FSX to use all your 4 cores or leave 1 (max. 2 out). The best way is to let the 1st physical core out!

E.g. your BIN entry will look like this if you want to use only 3 physical cores (leaving the first one out):

a) With HT: 01010100 = 84

b) Without HT: 1110 = 14

The same math goes for all processors, you just have to know how many cores you have.

 

You will need this entry if you have the BOXED version of FSX!

If you run FSX:SE the default setting is AM=84 for HT on or 14 for HT off.

Regards,

Gerald

[SteveW 1,792]

1 hour ago, Hypofx said:

Hi Stevie,

Tried few settings but a bit unclear- i have 6800K HT off what should be the AM? and is it worth to check with HT on ??

 

6 core 12LPs?

HT disabled Affinity Mask 011110=30

HT enabled AM=00,01,01,01,01,00=340

 

[GEKtheReaper 364]

1 hour ago, SteveW said:

6 core 12LPs?

HT disabled Affinity Mask 011110=30

HT enabled AM=00,01,01,01,01,00=340

 

@SteveWThank you for pointing me in the right direction. I overlooked the fact that he has a 6Core CPU (I partly edited my post above).

Do you think FSX will benefit of the 6 Cores? I at my end see no effect in using 2 or 4 cores of my 4790. The SIM always loads faster with more cores (event the logical ones boost the loading up) but the AVG FPS won't budge. I think I was getting the opposite selecting more cores (just physical ones) and the SIM stuttered.

I think he's best performance will be actually OC the CPU (i've seen i5 OC to 4+Ghz performing way better then mine i7).

[Hypofx 10]

Thanks guys all those GREAT explanations!!!! I used that site and currently HT OFF and i have this in fsx.cfg I have FSX SE 

[JOBSCHEDULER]
AffinityMask=62

Im going to change it based on your posts and check the result.

 

 

 

[SteveW 1,792]

Yes the renderer fps is determined by the GPU and then the CPU single thread performance and is leanest over four LPs. Allowing more logical processors than four extends the background loading performance but can at the same time drag the renderer back.

[GEKtheReaper 364]

@SteveWI kind of made this experience (that's why I asked if you think the sim will benfit of more cores).

I have a i7 4790 (no k) with 8 LP a base clock of 3.6GHz with a boost up to 4GHz.

On a vanilla FSX:SE I reached the best AVG frames using AM20 (2 LP) and the worst using AM85 (4LP). This was due the fact that the BOOST freq. is applied taking into consideration TDP, no. of CORES, CPU load,... .

So to speak, if I loaded only 2LP, the CPU used the extra TDP headroom to apply a 3,93GHz clock (with 3LP it applied a max of 3,83GHz and with 4LP it got up to just 3,75GHz). This clock increase did give me ~2 AVG FPS more per each 100MHz of boost (4LP=30FPS, 3LP=32,xx FPS, 2LP=35FPS).

[oscarduran10 3]

Never understood why people us affinitymask on a 4 core. It just causes blurries with cpu intensive airplanes and scenery cuz all 3 cores are maxxed out its just common sense. Aerosoft airbus is a perfect example  how affinity mask is bad

[Bert Pieke 7,585]

46 minutes ago, oscarduran10 said:

Never understood why people us affinitymask on a 4 core. It just causes blurries with cpu intensive airplanes and scenery cuz all 3 cores are maxxed out its just common sense....

As you can tell from the above, it not "just common sense"..

[SteveW 1,792]

On ‎16‎/‎05‎/‎2017 at 1:06 PM, GEKtheReaper said:

@SteveWI kind of made this experience (that's why I asked if you think the sim will benfit of more cores).

I have a i7 4790 (no k) with 8 LP a base clock of 3.6GHz with a boost up to 4GHz.

On a vanilla FSX:SE I reached the best AVG frames using AM20 (2 LP) and the worst using AM85 (4LP). This was due the fact that the BOOST freq. is applied taking into consideration TDP, no. of CORES, CPU load,... .

So to speak, if I loaded only 2LP, the CPU used the extra TDP headroom to apply a 3,93GHz clock (with 3LP it applied a max of 3,83GHz and with 4LP it got up to just 3,75GHz). This clock increase did give me ~2 AVG FPS more per each 100MHz of boost (4LP=30FPS, 3LP=32,xx FPS, 2LP=35FPS).

That's correct, with less LPs allocated the sim takes longer to load data, and with turbo settings you can get the frequency drop. Problem with comparing performance of just pure fps is it makes no mention of background throughput. With slower data loading that is to say less background throughput leads to blurriness in the scene. Also if we reduce the number of cores available we find the sim piles all the same work onto less LPs ganging it all up onto the renderer, we get inconsistent fps - even though the turbo mode may push the fps up. Altering the frequency even a tiny bit can lead to changes in the coincidence of frames to monitor updates leading to appearance of improved performance where there is none. The sim works best split over four LPs, one LP per core on an HT enabled system with the overclock set to accommodate the extra heat (work) done by the HT enabled CPU. When making comparisons we have to be sure to have AA and other GPU stressing items relaxed or we won't see the CPU performance properly.

 

58 minutes ago, oscarduran10 said:

Never understood why people us affinitymask on a 4 core. It just causes blurries with cpu intensive airplanes and scenery cuz all 3 cores are maxxed out its just common sense. Aerosoft airbus is a perfect example  how affinity mask is bad

Good call. Although we are often referred with four core to put addons on core zero (0001) and allocate the other three with 14=1110 we can often see better performance by not using the AM (AM=0=1111) and allowing the sim to split across four cores, while instead corralling our addons onto the last two cores (1100). With four core HT enabled this equates to 85=01,01,01,01 and addons=10,10,00,00. Even if an addon shows as a meagre 5% in Task Manager it can mess up those first cores.

 

[davidzill 8]

Ok guys, plain and simple: Boxed FSX/Acceleration. HT on. Affinitymask=84. Is this the nominal, most well balanced setting? Or what should I set it to? I use AS16, EZCA2 w/ FSX

[Bert Pieke 7,585]

27 minutes ago, davidzill said:

Ok guys, plain and simple: Boxed FSX/Acceleration. HT on. Affinitymask=84. Is this the nominal, most well balanced setting? Or what should I set it to? I use AS16, EZCA2 w/ FSX

84 is a good "set and forget" setting for a quad core i7 CPU with HT on.

[SteveW 1,792]

 

7 hours ago, davidzill said:

Ok guys, plain and simple: Boxed FSX/Acceleration. HT on. Affinitymask=84. Is this the nominal, most well balanced setting? Or what should I set it to? I use AS16, EZCA2 w/ FSX

If we only want to use three cores with HT enabled to leave a core for addons then since we have HT On we can allow the sim to split over four LPs for rendering performance with 116=01,11,01,00 (best overall performance) or for increased background performance 92=01,01,11,00 (the rendering is helped by hyperthreading here on second core) - both leave the first core free. More background performance can be had from 252=11,11,11,00 still leaves core zero free (00 on right)  - place addons on 00,00,00,11. Otherwise use 85=01,01,01,01 uses four cores, but corral addons onto the unused LPs of the last two cores 10,10,00,00 or performance will suffer from any activity however slight is may seem. The problem with 84=01,01,01,00 is that it allows the sim to break over only three LPs forcing more work onto just one LP doing the rendering (LP2 third in from right).

[Bert Pieke 7,585]

116 makes sense to me,  92 looks potentially problematic..

But try them and see how they behave on your system.