231: AffinityMask for P3D V2

Although I said that FSX is still my preferred simulator platform, it doesn’t mean that I am totally giving up on P3D V2.   The two main issues that stop me from swtiching to this highly expected simulator are third-party addon compatibility and lagging FIP gauges.

For the first one, I couldn’t do anything but to wait for updates and fixes from either Lockheed Martin or related developers or we users ourselves.  For the second, after weeks of on-and-off trials and errors, I am glad to say that the lagging issue my FIPs encountered has been generally reduced to a minimum level that is now fully playable under P3D environment.

My recently purchased computer is running on an overclocked i7-4770K at 4.6GHz.  Graphics engine is a 3GB MSI GTX 780 Lightning card.  Both system and simulator storages use dedicated SSDs, plus 16GB 2133MHz memory.

Under such a decent computing setup, I was really disappointed when I found out that both the P3D and the FIPs, in particular, were performing unsatisfactorily.   On the contrary, FSX flies happily with almost all settings slided to maximum on my 30-inch, 2560 x 1600 monitor.  In addition, it doesn’t have any major compatibility issues to be solved.   Obviously, wishful thinking doesn’t up to par.

Not too long ago, I just discovered that P3D by default only runs on core 2, 4, 6 on my i7-4770K CPU, which I didn’t aware of in the first place because FSX operates all 8 cores out of the box.

After days of testing, I find using the last six cores from the CPU not only reduces the FIP lagging issue significantly but also improves the running smoothness of the P3D itself.

I implement the change by adding the AffinityMask parameter to the Prepar3D.CFG (C:\Users\<UserName>\AppData\Roaming\Lockheed Martin\Prepar3D v2) file as follows:


The parameter is put at the beginning of the file even though its location is not a concern.  My Post 10: fsx.CFG – AffinityMask has more details about the choice of value to be selected if recollection is needed.

Did find some arguments about the usefulness of the AffinityMask for P3D V2.    Why care as long as it works?

11 thoughts on “231: AffinityMask for P3D V2

  1. Very interesting read.

    I am hesitant to do anything with it today as I just got my system running FSX on Win 8.1 smoothly without any problems; but it may be of interest to some.

    Rick S.


    1. I haven’t switched to P3D yet as there are still quite some incompatibilities to be fixed. But it doesn’t hurt to give it another try and get it up and running once things are ready.


  2. Hi Tom,

    my fav. sim P3D v2 right now and what I can say concerning AffinityMask is, that it reduces blurries completely if they appear!
    It´s certainly is the only option to make the blurries disappear, no slider and other settings have any influence on it.
    So any user experiencing blurries should insert AffinityMask :-)



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