There are 4 ways to force MSFS to use the 3D cache cores, and they do matter - when I was developing my CYYJ Victoria airport I was running MSFS on my Win11 boot (I have dual boot with separate drives) where MSFS was lagging in dev mode, and when I made sure Win11 was set for 3D cache, the FPS jumped up quite a bit. So 3D cache is real, and matters a lot for MSFS.
- The Win11 way (that also works in Win10 BTW, I tested) is power=balanced, Game mode=on, HAGS=on, Game Bar=on. It enables core parking and makes sure MSFS runs on 3D-cache cores. Of course, AMD provisioning drivers are required.
- BIOS way: “prefer cache cores” set in BIOS instead of Auto or Driver. Doesn’t work on ASRock boards due to BIOS bug.
- Command line / .bat file way: you can set CPU affinity at launch or after a preset timer for both MSFS (CCD0) and all other software (CCD1). Doesn’t require anything else and is rock-solid. Power mode can be “ultra performance”, no need for “balanced”.
- Process Lasso software, which does the same as the command line. It’s easier to move all the third-party and system processes to CCD1 with the software, instead of tedious .bat file programming.
Method 1 is the simplest and the “official” way. The disadvantage is that you paid for 16 cores, and this method disables half of your CPU (core parking) that you paid for. For methods 2 to 4 the faster cores can still be used to run all the system processes and companion software - and I have a lot: motion simulator, ATC, in-flight tablet, vibration transducers etc. MSFS can have the entire CCD0 and all the rest can be dumped to faster CCD1 cores. It makes the most sense.
On my MSFS boot (Win10) I use a combination of methods 3 and 4. I also have a .bat file to relaunch MSFS if needed, it removes the affinity settings and resets it after a pause. Otherwise MSFS crashes on launch. You can’t assign affinity for MSFS at start (needs to be after about 30 seconds) and you can’t force it out from core 0, which is OK because it’s on CCD0. code 0 runs most system processes though, but almost all of them can be forced out by Process Lasso to CCD1. I think there are 2 very low-level system processes that can’t be reassigned to other cores, but they don’t matter much.
But if you don’t force one of the methods, by default MSFS will run on the faster CCD1 cores which are not 3D-cache, which are the whole point for the 7950X3D CPU.