Must be my right brain dominance or something, but I've read so many posts about this and still do not understand what exactly to enter for the AFFINITYMASK setting. I have a dual processor system, each processor has 4 physical cores, and hyperthreading is on (I have no idea how to turn it off). What do I actually enter here?[JOBSCHEDULER]AffinityMask=????????If your reply contains anything more than just a number, you'll confuse me beyond belief :(. Thanks for your help.- Jev McKee

I am no expert at this so someone please correct me. First, you turn off hyperthreading in the bios. Then, you'll have 8 physical cores so I guess you're affinity mask should be 255 to have fsx use all cores. This is because in binary it would look this:11111111Each "1" represents which core can be used by the game (read from right to left). Converting this number to decimal yields the number 255.

I am no expert at this so someone please correct me. First, you turn off hyperthreading in the bios. Then, you'll have 8 physical cores so I guess you're affinity mask should be 255 to have fsx use all cores. This is because in binary it would look this:11111111Each "1" represents which core can be used by the game (read from right to left). Converting this number to decimal yields the number 255.

If you turn HT off you will have 4 physical cores. This can be verified by looking at your task manager. With it on it will show 8.With HT ON255 - all 8 in use254 - 7 in use with the first remaining free252 - 6 in use with the first entire CORE remaining free127 - 7 in use with the last remaining free63 - 6 in use with the last entire CORE remaining freeHT OFF1 = 1 core 00013 = 2 cores 00117 = 3 cores 011112 = 2 cores last 110014 = 3 cores last 111015 = 4 cores 1111

If you turn HT off you will have 4 physical cores. This can be verified by looking at your task manager. With it on it will show 8.With HT ON255 - all 8 in use254 - 7 in use with the first remaining free252 - 6 in use with the first entire CORE remaining free127 - 7 in use with the last remaining free63 - 6 in use with the last entire CORE remaining freeHT OFF1 = 1 core 00013 = 2 cores 00117 = 3 cores 011112 = 2 cores last 110014 = 3 cores last 111015 = 4 cores 1111

How would Jev Write his affinity value since he has 2 4 physical core CPUs? Would it be 255 or something different (with hyperthreading off and considering he wanted to use all physical cores).

I was hoping the experts would add a little detail here but I hope this doesn't confuse the question - I don't really know this area - just am trying to parrot what I've read. Apparently we want to keep FSX away from using Physical Core #0 by using the Affinity Mask - example, using 14 not 15. Core #0 is then utilized mostly by the OS for it's disk, ethernet, and other peripheral device tasks as well as having some of the fibers (or threads??) running on it. Then we want FSX to use Physical Cores# 1,2,3... for graphics rendering, aircraft flight sim, AI, ATC, etc with #2,3,... doing texture loading and maybe some support tasks with Physical Core#1 running at 100% and Core#2,3,... running at varying percentages up to 100% when in very dense scenery areas with lots of new textures needed as we move along. If we could, we would keep the cores assigned in a fixed way - never letting the OS change them - but Affinity can't really guarantee that so the Performance Monitoring doesn't always look right. Make any sense? Some folks find this is important to both frames per second or at least to stutter reduction performance - and others don't. I don't think that FSX itself directly can use more than three cores (plus the OS core #0) but there really isn't a way to watch that on any Performance Monitor. Even then, having more than four cores still might be good because support tasks that the OS needs done might be assisted by the additional cores. If we could only watch the various code pieces as they execute on the entire CPU!

I was hoping the experts would add a little detail here but I hope this doesn't confuse the question - I don't really know this area - just am trying to parrot what I've read. Apparently we want to keep FSX away from using Physical Core #0 by using the Affinity Mask - example, using 14 not 15. Core #0 is then utilized mostly by the OS for it's disk, ethernet, and other peripheral device tasks as well as having some of the fibers (or threads??) running on it. Then we want FSX to use Physical Cores# 1,2,3... for graphics rendering, aircraft flight sim, AI, ATC, etc with #2,3,... doing texture loading and maybe some support tasks with Physical Core#1 running at 100% and Core#2,3,... running at varying percentages up to 100% when in very dense scenery areas with lots of new textures needed as we move along. If we could, we would keep the cores assigned in a fixed way - never letting the OS change them - but Affinity can't really guarantee that so the Performance Monitoring doesn't always look right. Make any sense? Some folks find this is important to both frames per second or at least to stutter reduction performance - and others don't. I don't think that FSX itself directly can use more than three cores (plus the OS core #0) but there really isn't a way to watch that on any Performance Monitor. Even then, having more than four cores still might be good because support tasks that the OS needs done might be assisted by the additional cores. If we could only watch the various code pieces as they execute on the entire CPU!

I'll try when I have time a value of 14 or 15 and see which one works for me better.

I was hoping the experts would add a little detail here but I hope this doesn't confuse the question - I don't really know this area - just am trying to parrot what I've read. Apparently we want to keep FSX away from using Physical Core #0 by using the Affinity Mask - example, using 14 not 15. Core #0 is then utilized mostly by the OS for it's disk, ethernet, and other peripheral device tasks as well as having some of the fibers (or threads??) running on it. Then we want FSX to use Physical Cores# 1,2,3... for graphics rendering, aircraft flight sim, AI, ATC, etc with #2,3,... doing texture loading and maybe some support tasks with Physical Core#1 running at 100% and Core#2,3,... running at varying percentages up to 100% when in very dense scenery areas with lots of new textures needed as we move along. If we could, we would keep the cores assigned in a fixed way - never letting the OS change them - but Affinity can't really guarantee that so the Performance Monitoring doesn't always look right. Make any sense? Some folks find this is important to both frames per second or at least to stutter reduction performance - and others don't. I don't think that FSX itself directly can use more than three cores (plus the OS core #0) but there really isn't a way to watch that on any Performance Monitor. Even then, having more than four cores still might be good because support tasks that the OS needs done might be assisted by the additional cores. If we could only watch the various code pieces as they execute on the entire CPU!

You´re saying that we should keep FSX away from physical core 0, but this runs the FSX main thread on my system and core 1 is free. Does this mean that I have to change my sffinity mask settin, so that core 0 is free?

You´re saying that we should keep FSX away from physical core 0, but this runs the FSX main thread on my system and core 1 is free. Does this mean that I have to change my sffinity mask settin, so that core 0 is free?

There is no "correct setting".Try 13 and 14 and decide which works better on your system (or go back to 15, the default). :(

There is no "correct setting".Try 13 and 14 and decide which works better on your system (or go back to 15, the default). :(

Ok, I´m using 13 for a long time and it´s working somehow nice what I get performance wise out of my semi-optimal FS system, but I just thought...

How would Jev Write his affinity value since he has 2 4 physical core CPUs? Would it be 255 or something different (with hyperthreading off and considering he wanted to use all physical cores).

Call me daft, but I still don't understand whether I enter a binary or decimal number in the cfg. Also, I cannot edit the bios. I'm on a dual-boot Mac and have no idea how to turn off hyperthreading.If I want to leave my first core free (for system stuff, etc.) and have the other 7 cores available, what do I enter?Please, please just give me a number to put[JOBSCHEDULER]AffinityMask= <<<< HEREThanks again. I appreciate the help.- Jev McKee

Call me daft, but I still don't understand whether I enter a binary or decimal number in the cfg. Also, I cannot edit the bios. I'm on a dual-boot Mac and have no idea how to turn off hyperthreading.If I want to leave my first core free (for system stuff, etc.) and have the other 7 cores available, what do I enter?Please, please just give me a number to put[JOBSCHEDULER]AffinityMask= <<<< HEREThanks again. I appreciate the help.- Jev McKee

I am no expert at this and don't know how it would work on your setup since you have two cpus. I guess in binary it would be 0101010101010100. This will leave your logical cores 0 and 1 not working in fsx. Then, each physical core will be active but each virtual core would be off which bojote said is the correct way to do it with hyperthreading on (at least in my case with 8 logical cores). This number in decimal would be 21,844.

Just did a quick test and it seems that my best configuration right now is with hyperthreading off and affinity of 13. While flying I had pretty much the same rates (like 1 extra fps) but while on the ground at fs dreamteam kfll runway 9l, I had about 3 fps better than in other configurations and my frames remain pretty stable.

Is it possible to arrive at a conclusion and just have the correct or best affinity mask values forhyperthreading on = ?hyperthreading off= ?

No!Remember this is FSX, "The Hog" - and nothing is was it seems to be, and nothing is sure, and nothing is the same on the billions of FSX rigs out there!Did it help You?

No!Remember this is FSX, "The Hog" - and nothing is was it seems to be, and nothing is sure, and nothing is the same on the billions of FSX rigs out there!Did it help You?

This is very true. The only way to know is by testing it yourself. And if you're referring to me, yes, it did help me to set the correct affinity mask as now I get around 3 more frames on the ground and the frames are more stable.

Will turning off HT slow down other non FS software though?

Well, I do not have a CPU with HT (mine is too old), but I think it is different from programm to programm. Take FS9 for example. FS9 won´t use HT, cause it´s not written for a multi core environment (in 2002/3 there weren´t hardly any 64 bit systems and the most commom CPUs were single core or more expensive dual core.) FS9 will only use one core, no matter whether you have 4 or 8 cores. As long as you don´t run heavy CPU demanding multi core programms like some CAD design programms you won´t see much difference.FSX uses 3 cores, so without HT there will be one left. So you can enable HT, but you should check that FSX uses only the physical and not the virtual cores.