From what you already showed me, you are using a virtual machine (VM) allocated with 8 cores. However these are actually four cores with eight threads from a 12 core. Supporting that VM is a 12 core 24 thread CPU. If they tell you you have four cores, and the system shows 8 virtual cores then your VM is using 8 of those 24 threads. So although the VM does not support HT the CPU is virtualizing 8 cores in your VM from 4 cores. In that case you need to be sure the simulator uses one of the first two virtual cores. So it would be better to set the affinity mask to 125=01,11,11,01 which means the simulator will not share the first real core with two threads so that the first simulator thread (main rendering task keeps fps) will have full unshared use of a core.

Let me put it another way:

The Intel site shows the Intel Xeon E5-2678 V3 is a 12 core 24 thread Processor.

Your shot of Task Manager shows 8 virtual processors in use for your Virtual Machine (VM):

Your supplier says your VM is using four cores. If that is true then those four cores must then be using two Virtual Processors each to make up the eight Virtual Processors shown in Task Manager.

Given this information I would use AffinityMask=125 in the Prepar3D.cfg. That ensures the task responsible for making frames (fps) is not sharing its physical core with another task. That will help maintain your fps as much as possible.

 

2 hours ago, SteveW said:

If it is four core, eight threads (logical processors) use AM=125=01,11,11,01.

Just did more testing, same issues occur, 30+ when displays are off, 18-20 when displays are on

OK so you got the AM sorted out? If so let's look at the displays - which aircraft?

1 minute ago, SteveW said:

OK so you got the AM sorted out? If so let's look at the displays - which aircraft?

PMDG and Qualitywings. Aerosoft is like a 2-4 fps drop from time to time

The PMDG and Qualitywings are the big ones that take fps when displays are on

1 hour ago, SteveW said:

Let me put it another way:

The Intel site shows the Intel Xeon E5-2678 V3 is a 12 core 24 thread Processor.

Your shot of Task Manager shows 8 virtual processors in use for your Virtual Machine (VM):

Your supplier says your VM is using four cores. If that is true then those four cores must then be using two Virtual Processors each to make up the eight Virtual Processors shown in Task Manager.

Given this information I would use AffinityMask=125 in the Prepar3D.cfg. That ensures the task responsible for making frames (fps) is not sharing its physical core with another task. That will help maintain your fps as much as possible.

 

So if the cores were 12, what would the affinitymask be with and without ht? Just gonna test something really quickly

Supposing your supplier is correct you have four cores allocated, and the task manager display shows eight virtual processors, that is the same as any four core CPU with HT which we would say has four physical cores with two logical processors (LPs) each making eight LPs. In that case with Prepar3D we would allocate six of those LPs in the AM so as to avoid sharing the first giving us an AM=125 in the Prepar3D.cfg. Your PC actual core count is 12 cores giving 24 LPs, your virtual machine (VM) only has 8 of those 24. Even if there are 8 physical cores the AM=125 would still work well giving six to P3D, more does not really help. So as a say, it's best to get that right before moving on to other issues.

Now as far as the drop in framerate is concerned using those add-on aircraft the displays will naturally hit your fps - that's a given. However, in the PMDG FMS I believe you can allocate how much time the displays are updated, in which case you can reduce the load from those displays that way.

11 hours ago, SteveW said:

Supposing your supplier is correct you have four cores allocated, and the task manager display shows eight virtual processors, that is the same as any four core CPU with HT which we would say has four physical cores with two logical processors (LPs) each making eight LPs. In that case with Prepar3D we would allocate six of those LPs in the AM so as to avoid sharing the first giving us an AM=125 in the Prepar3D.cfg. Your PC actual core count is 12 cores giving 24 LPs, your virtual machine (VM) only has 8 of those 24. Even if there are 8 physical cores the AM=125 would still work well giving six to P3D, more does not really help. So as a say, it's best to get that right before moving on to other issues.

Now as far as the drop in framerate is concerned using those add-on aircraft the displays will naturally hit your fps - that's a given. However, in the PMDG FMS I believe you can allocate how much time the displays are updated, in which case you can reduce the load from those displays that way.

In PMDG i have it set to 12 FPS on the Displays, but even when they are still on it's the same way. I've tried 30,55,15,12 FPS in the performance menu and it's all the same.

Just to mention these fps drops happen at default airports.

Prepar3D v5 scenery is double the size of older P3D versions. Perhaps the displays just have more work to do in v5. Did you have Prepar3D v4 previously?

1 hour ago, SteveW said:

Prepar3D v5 scenery is double the size of older P3D versions. Perhaps the displays just have more work to do in v5. Did you have Prepar3D v4 previously?

Yes I did, frames were capped at 20. When I got V5, I got 35+ fps, but since October 8th, fps has been dropping tremendously. It's slowly creeping back up to V4 fps.

i wonder if something changed on October 8th? In Control Panel choose Uninstall a program (under Programs). In the window, click the title of "Installed On" column. Have a look around that date for anything that could be related to performance.

Another idea is to install an older Nvidia driver: Locate 451.67 on the Nvidia site and download that. Run that and choose the custom, then check the Perform clean install. Later drivers have been giving problems to some P3D installations.

9 hours ago, SteveW said:

i wonder if something changed on October 8th? In Control Panel choose Uninstall a program (under Programs). In the window, click the title of "Installed On" column. Have a look around that date for anything that could be related to performance.

Another idea is to install an older Nvidia driver: Locate 451.67 on the Nvidia site and download that. Run that and choose the custom, then check the Perform clean install. Later drivers have been giving problems to some P3D installations.

Same thing, so I dont believe it's a graphics card driver. Besides I get little to no use on graphics card when I'm running P3D. Legit P3D only uses 0.1% of my graphics card.

Maybe ask at the PMDG forum, since it seems to mostly affect your PMDG aircraft perhaps it is something they know of?