Just a sec. At the top of this topic Finn, you say the affinitymask should be set at 254 in your first post on this topic and then in another where you reply to RPRIEVER, who also has 8 cores like me, you say it should be set at 127. I am very confused now! I have 8 CPU cores according to the CPU usage history in the task manager. Should I be setting it at 254 or 127?

No...

 

The first examples are what people normally have done according to the number of physical cores their CPU have i.e

 

4 Cores = 14

6 Cores = 62

8 Cores = 254

 

What I suggest is to spare one core by setting:

 

4 Cores = 7

6 Cores = 31

8 Cores = 127

 

I Your case I don´t know if You have 8 physical cores or just 4 physical + 4 virtual cores due to Hyperthreading beeng enabled.

 

Finn Jacobsen

After reading this post I changed my i5 4 core Affinity Mask setting from 14 to 7 just out of curiosity really. I have to say I have had a smoother flight experience, no little stutters I would occasionally get. Will keep at 7 for a while but so far very pleased.

Finn, when I start the task manager and click on the performance tab, I see 8 cores under cpu usage history. Does that mean I have 8 cores, or should I be looking elsewhere for that info? I am running a Windows 7 64-bit system with an Intel Core i7 870 processor at 2.93GHz. When I get my system info by right-clicking on the "computer" option in the Windows menu, it actually says "Intel Core i7 CPU @ 2.93GHZ 2.93GHz. I also have 12GB of RAM.

Finn, when I start the task manager and click on the performance tab, I see 8 cores under cpu usage history. Does that mean I have 8 cores, or should I be looking elsewhere for that info? I am running a Windows 7 64-bit system with an Intel Core i7 870 processor at 2.93GHz. When I get my system info by right-clicking on the "computer" option in the Windows menu, it actually says "Intel Core i7 CPU @ 2.93GHZ 2.93GHz. I also have 12GB of RAM.

As far as I can tell, searching  the internet, Your CPU is a quad core (4 physical cores).

This means that hyperthreading is enabled in Your bios.

 

I suggest You disable hyperthreading in Your bios and then set Affinitymask=7

If Your unsure, or feel bad changing stuff in the bios, simply try setting Affinitymask=7 and don´t touch the bios settings

 

Finn Jacobsen

How would you go about changing the hyperthreading setting in the BIOS?

Depending on what Bios You have. Hyperthreading can be found on thr CPU setup page where it can be toggled on/off or enable/disable.

 

Finn Jacobsen

 

 

Remember that when presented in binary, the last digit represents the first core .

 

For example, to enable FSX on cores two, three and four on a quad core non-hyperthreaded cpu,

 

the binary is 1110, and the decimal affinity mask setting is indeed 14.

 

Some of the examples posted in this thread instruct the CPU to use three cores, but do not exclude core one.

 

Try to keep the first CPU core for windows and ancillary programs. Exclude FSX from it.

 

Hopefully now everybody's confused, but if not, it should also be remembered that cores one, two three & four are actually cores 0,1,2 & 3.

 

Binary converter:  http://acc6.its.brooklyn.cuny.edu/~gurwitz/core5/nav2tool.html

 

or the easy route:

 

Flight Simulator X (FSX) & Prepar3D (P3D v1 / P3D v2) - Affinity Mask Calculator:     http://www.gatwick-fsg.org.uk/affinitymask.aspx?SubMenuItem=hardware

 

 

 

 

 

 

Okay, so I've disabled hyperthreading in the BIOS and set the affinitymask value to 14. My video card drivers are up-to-date and I've set up the NVidia Inspector as per Ryan's recommendations. Lets see what this does!

Okay, so I've disabled hyperthreading in the BIOS and set the affinitymask value to 14. My video card drivers are up-to-date and I've set up the NVidia Inspector as per Ryan's recommendations. Lets see what this does!

 

Better try with Affinitymask=7.

 

FinnJ

 

 

 

Better try with Affinitymask=7.

 

FinnJ

 

Using a mask of seven ( binary 0111) will mean that FSX is assigned to the first three cores, and is sharing cpu resources with Windows and everything else on your system, leaving the (already under-utilized) fourth core twiddling its thumbs.

 

Mask 14 tells FSX to use the second, third and fourth cores, leaving the first one for Windows, Firefox, whatever...

 

Bit of a no-brainer, and proven to work.

 

Try both and compare usage under Task Manager, and keep an eye on the graphs before, during and after loading FSX.

 

 

 

 

 

 

 

 

Using a mask of seven ( binary 0111) will mean that FSX is assigned to the first three cores, and is sharing cpu resources with Windows and everything else on your system, leaving the (already under-utilized) fourth core twiddling its thumbs.

 

Mask 14 tells FSX to use the second, third and fourth cores, leaving the first one for Windows, Firefox, whatever...

 

Bit of a no-brainer, and proven to work.

 

Try both and compare usage under Task Manager, and keep an eye on the graphs before, during and after loading FSX.

 

 

the theory behind Your statement is fine, but as told in the opening post, the Majestic Dash8-Q400 had similar freezing and for most going from Affinitymask=14 to 7 helped alot, also giving a more smooth running FSX.

 

Apart from the Dash8-Q400 running without freezes/pauses, I fell FSX running smoother and cannot see any drop of FPS compared to 14.

 

Again remember that from the outset FSX did not support multicores, that was something they added (though not fully) with SP2/Acceleration.

 

 

Finn Jacobsen

Can't comment on the Q400, but I do know that assigning an Affinity Mask = 7 is akin to running FSX on a tri-core cpu.

 

With regard to PMDG products (in whose forum this thread resides), I've found the 14 mask to be very well suited.

Can't comment on the Q400, but I do know that assigning an Affinity Mask = 7 is akin to running FSX on a tri-core cpu.

 

With regard to PMDG products (in whose forum this thread resides), I've found the 14 mask to be very well suited.

Stephen....

 

As such I do agree with You

 

I have used affinitymask=14 for a long time, until I got the Majestic Dash8-Q400, where I, like others, had some freezing issues.

The developers told us to try affinitymask=7 inorder to keep one core "FSX free" so that their special moduel(s) coulod run their without interference from FSX, and it has worked for me and for others.

 

Since I often fly the Q400, I have affinitymask=7 and don´t change it, also becasue it has not have any negative effect on performance or smoothness. Actually I have now almost no stutters.

 

The 777 was installed on my system after I have set affinitymask=7, and I never ever had a freeze with the 777.

So when I read that some usres have this issue, I simply pointed them towards trying this and atleast one user seems to have succes with it.

 

Don´t aks me about why this should work, but the PMDG 777 also runs alot of processes outside or around FSX, so maybe these doesn´t like to run on the same core as FSX.

 

It is only meant as a possible fix for those having the problem.

 

 

Finn Jacobsen

OK Finn - In the interests of balance and inquiry, I'm gonna give it a try next flight.

Let me know how it goes.