One of the draws toward Prepar3D was that it would offload the CPU of computations, and move them on the GPU. It was a fairly big reason why I bought P3D v3. But yet I'm really not finding an improvement in this department. Take a look at this screenshot below, detailing my CPU and GPU usage.

 

 

 

I have one physical core doing most of the load, and the other three physical cores sharing the rest. This is what I would typically see in FSX. But then I looked at my GPU usage. Only 54% usage! With a 3 year old GTX 660. And my frames are unlocked, but I'm only seeing 17 FPS, which was near the high end of what I was experiencing here. I had plenty of VRAM left. My frames would usually bounce between 10-15 FPS, with some stutters dropping me to 5 FPS at times on approach.

 

Moving the sliders left did very little. I manage AI traffic, and only about 60 aircraft existed at this time of the screenshot, so the FPS impact would be minimal. I tried updating my drivers, but that did nothing. Locking the frames even dropped them worse! Turning off Active Sky Next did nothing, and I didn't expect FPS to increase because the cloud sprites seemed to be rendered mainly on the GPU. My hyperthreaded CPU is overclocked to 4.7 GHz, so there is no more headroom to increase CPU power.

 

Lastly, is it the aircraft? I would think not. The Airbus has always been light on resources, and my frame rates are very satisfying in FSX (DX10). What would be so modeled so significantly different to cause such poor performance.

 

I feel something is clearly amiss here, but I've tried crossing all my T's and dotting all of my I's. No config tweaks, except AffinityMask to rid myself of the horrible default setting where all of my logical cores were utilized (major stutterfest). No full sliders right. No SGSAA. No AA > 4X MSAA.

 

You might try hyperthreading off in the BIOS. No promise it will help as this is system dependent, but it did help on my system to smooth core usage and better feed the GPU. Others reported similar findings. For hyperthreading off, remove any affinity mask setting.

 

Kind regards, Michael

You might try hyperthreading off in the BIOS. No promise it will help as this is system dependent, but it did help on my system to smooth core usage and better feed the GPU. Others reported similar findings. For hyperthreading off, remove any affinity mask setting.

 

Kind regards, Michael

 

Maybe. I'm not sure if I would see any improvement, because I exclude P3D from running on the logical cores.

You might try hyperthreading off in the BIOS. No promise it will help as this is system dependent, but it did help on my system to smooth core usage and better feed the GPU. Others reported similar findings. For hyperthreading off, remove any affinity mask setting.

 

Kind regards, Michael

Hey Michael,

 

Do you have an I7-2600K?...can you provide some stats on frame rate under various conditions? I appear to be in pretty much the same boat as you, hardware wise.

 

Thanks,

Chas

It seems that P3D v3 remains CPU-bound in heavy scenary. This is not suprising. When you CPU is overloaded, your GPU will become underloaded as, likely, CPU could feed enough jobs to GPU.

Fly into a heavy thunderstorm with Max cloud detail on and watch your GPU go to 100% usage real quick.  

 

Your simulation is unbalanced it would seem.   Hyperthreading off will help I believe.   I shut my HT off on my 6 core i7 3930k and got better performance and cooler temps on the chip itself.

 

AI traffic is murder, period.   It is 99% CPU driven which is why it should be one of the first things to go.   Car traffic too.    On my rig, I typical do about 30 FPS in the PMDG 737ngx  at most airports with AI traffic off.  When it is on, if I get more than 40 airplanes in the area it starts to degrade rapidly.

 

Older video cards do not handle Tessellation well and I would recommend pulling that as far left as you can bare.      

 

These have been some of my experiences but mileage will vary from build to build.   There is no one size fits all.

I have a i7 4790 @ 4.4 and a GTX 780 and use quite maxed out graphic settings: still, the GPU load is only around 70% in heavy situations (where performance drops to mid to low twenties). So the GPU is sleeping a lot. I tried a GTX 980 Ti last week and obviously it didn't make any difference in performance. The 980 Ti only started to show its strength when I used very high AA settings.

 

P3D is still very CPU dependent.

Hey Michael,

 

Do you have an I7-2600K?...can you provide some stats on frame rate under various conditions? I appear to be in pretty much the same boat as you, hardware wise.

 

Thanks,

Chas

I have the i7-2600 non-K (non-overclockable) which I bough by intention as I never meddled with overclocking. Here's a representative result on my system.

 

Takeoff at FB KSFO HD with ORBX NCA in the background, UT2 both (airliners/GA) at 45 % , 4x SGSSin NI (3440x1440), HT off, no AM but process priority set to high, under Prepar3d2.5, all scenery settings except Mesh (5 m) maxed, but bathymetry off, Alabeo C172, I get around 18-20 fps. Drops down up to around 15 over KSFO downtown, not excellent but still flyable.

 

I might add I use a hardware panel, thus no panel on display at all, just scenery. 

 

Prepar3d3 is doing better, but I don't have reliable figures so far to share.

 

Kind regards, Michael