CPU usage and Frame Limiter

[pabloa2]

I came across some information that I though might be helpful to others in this forum. I installed Prepar3D v3.35 recently and ran into the same issue I have been having with v3.x. Namely, Core 0 on the CPU (Intel i7 4810QM - Quad Core) was always at 100 percent usage. I seem to have found a "fix" for the issue, oddly enough, having to do with the frame limiter I was using. I have always used MSI Afterburner to limit frames through Rivatuner Statistics Server (the built-in on screen display server). I am running at 70 hz through HDMI and was limiting frames to 35, exactly half the monitor refresh rate. I had pretty good performance so I never thought about changing the frame limiter. Well, today I decided to limit frames through NVIDIA Inspector and lo and behold, cpu usage on Core 0 went down to 70-80 percent. Not only that but the sim seemed to run much smoother with less "hiccups" when panning etc. I can say without a doubt that when I use MSI Afterburner to limit frames I end up with Core 0 at 100 percent usage, which causes heat to rise etc, which causes throttling. It is obvious that they use different methods to limit frames and I think that NVIDIA Inspector uses a hardware mode to limit frames which must send maybe a "fake" refresh rate or something to DirectX. Anyways, I hope this helps someone as it definitely made my experience more enjoyable. No more 100 percent usage on Core 0, less heat, smoother sim overall.

My Settings - Frames limited in Prepar3d to 60 Hz, Frames limited in NVIDIA Profile Inspector to 35 Hz (Half monitor refresh rate), VSYNC OFF

Remember, if you disable Aero Desktop Composition you will have severe screen tearing in Windows 7. Aero must be TURNED ON for Prepar3D.

Nvidia Inspector Latest Version Link

http://orbmu2k.de/tools/nvidia-inspector-tool#more-244

Hardware Specs:

OS - Windows 7 x64 Ultimate
CPU - Intel i7 4810QM (Mobile Quad Core w Hyperthreading) HT is turned off in BIOS
RAM - 2x8 GB 1833 mhz Corsair Sodimm Dual Channel
GPU - NVIDIA GTX980M
HD - Micron 256 GB SSD

[AnkH]

Interesting find. One remaining question: do you use rather high settings? A lot of addons? I wonder, because using the internal limiter at 60FPS results in my case in more blurries when flying low and fast compared to 30FPS. If it would not be to big of an hazzle, it would be nice if you could test this on your setup (comparing 60FPS and 30FPS via internal P3D framelimiter, external settings the same). Basically, I do not see any reason why the external frame limiter should be that much lower than the internal one, why do you have it like this?

[pabloa2]

I have tried every setting combination possible to find the "best" experience I could. I guess "best" would be a relative statement. For me I prefer a steady framerate over anything else with as much additional eye candy as possible. When I run with unlimited frames in Prepar3D I get more stutters, it's not a question, much more stuttering. When I set it to 60 it seems to smooth the sim out much more no matter what I set an external limiter to. There may be minor blurries but I don't notice them enough to sacrifice the "smoothness" of setting it to 60 in Prepar3d. I don't know how they buffer frames in Prepar3d but the developers should take some hints from some of the Tier 1 game developers out there because no other game or sim I have played has the stuttering frames problem. Or, even better, offer us a simple toggle for Full-Screen Exclusive mode so NVIDIA users can use the half-vsync option. That would be ideal and I have absolutely no idea why they don't allow full-screen exclusive mode. It is a no-brainer. With half-vsync on NVIDIA we would have zero stutters so why they haven't implemented it like FSX is beyond me.

[pabloa2]

Update:

So, after playing around with the settings and nvidia profile inspector I found a way to get a pretty much stutter free flight. Since Nvidia Profile Inspector has some strange values for the frame limiter I decided to limit frames to 31.5 Hz in Nvidia Profile Inspector and created a Custom Monitor Resolution of 1920x1080p @ 63 Hz essentially creating a "faked" half-vsync situation. I set unlimited frames in Prepar3D and VSYNC and Triple Buffering ON. The only stutters I get now are while turning on the ground and flying close to the ground. Other than that, smooth as butter. Hope this helps someone.

Note: Added bonus of this method is that CORE 0 is no longer at 100 percent usage, in fact it is almost half that, hovering between 50-70 percent.

[FSTramp]

I do not understand the bonus. Core 0 is blocked by waiting for the graphics card and sleeps. During this time he is useless. What benefits does this have? A rhetorical question.

[pabloa2]

It's not really rhetorical. You cannot get smooth framerate in Prepar3d unless you can maintain your monitor refresh rate (in my case I cannot set my monitor to 30 hz) OR you are running at some fraction of your monitor refresh rate, like 1/2, 1/4 etc. You will have stutters period, unless of course you have a G-Sync monitor. The actual question should be "why don't the Prepar3D developers simply offer a fullscreen exclusive mode so NON-GSYNC users can just use the half vsync option?" There are major benefits to CORE0 not running at 100 percent for no apparent reason, such as less heat, less thread collisions and so on. What is funny to me is that when using NVIDIA inspector to limit frames I get a steadier framerate PLUS the cpu is not running at 100 percent. When I use the built-in limiter or any other limiter performance goes down and there are still stutters AND CORE0 is at 100 percent. This wouldn't be an issue if Prepar3D wasn't so demanding on a system but the only way to keep 60 Hz steady is by shelling out a lot of money on new hardware, simple as that. Not everyone has a thousand dollars to drop just to have a non-stuttering framerate. The only way that I have found is what I listed above. Create a custom resolution with 63 Hz refresh rate, use NVIDIA Inspector to limit frames to 31.5 Hz and set VSYNC and Triple Buffering ON. Like I said, this is the ONLY sim or game I have played that has a problem with stuttering frames and that could be fixed for the majority of users by simply offering a full-screen exclusive mode. Instead of defending stupid developer decisions you should be asking why they removed such an important feature. Adaptive VSYNC and half-refresh ONLY work in full-screen exclusive mode. Why would they remove it, essentially breaking a stutter free experience for most users?.. That is the important question.

[whitav8]

Could you please explain the significance to the 31.5HZ and 63HZ choices -- why does that work when 30/60 won't without fullscreen exclusive.

[pabloa2]

The significance is that the values for the framerate limiter in NVIDIA inspector are kind of strange for example:

27.4
28.5
29.5
30.5
31.5
32.6

Since I cannot make a custom refresh rate that has a decimal number then I have to pick a frame limit that is exactly half a whole number. I tested 28.5, 29.5, 30.5, and 31.5 and 31.5 with a 63 Hz Monitor refresh rate gave me the best result. What is odd is that I can now set all my Scenery Sliders to maximum with no perceptible framerate loss. Right now I am running with all scenery sliders at max, lighting at default, clouds at maximum coverage 100 mi, with NO perceptible framerate loss. To top it off none of the cores on my i7 4810QM goes over 90 percent. Don't ask me why the performance gain is so huge because I have no idea but it is what it is. Unless you try it yourself then don't be an annoying naysayer just for the sake of it. Even at O'Hare, NO perceptible framerate loss at those levels. Don't believe me? Try it out.

-- My settings right now--

Nvidia Inspector

Frame-Rate Limiter- 31.5
Transparency Anti-Alias - 2x Sparse Grid Super Sampling Anti-aliasing
Pre-rendered frames max - 1
Trilinear Optimization - Off

Custom Monitor Resolution - 1920x1080 @ 63 Hz

Prepar3D Config

UseGlobalTerrainView=True
TextureMaxLoad=9

Prepar3D Settings

Framerate - Unlimited
VSYNC - OFF
Texture Resolution - Ultra
MSAA - 2x
FXAA - OFF
Anisotropy - 16x
Tesselation - On
LOD - Ultra
Water - High (ultra hides the on-screen display of msi afterburner so I don't use it)
Bathymetry - OFF
Scenery Complexity - Extremely Dense
Autogen Veg - Very Dense (could have it at extremely dense but looks unrealistic)
Autogen Buildings - Very dense (same as autogen veg)
Special effects detail - High
Special effects distance - High
All Lighting - Default except SimObjects cast shadow
Clouds - 100 MI Maximum Coverage

[whitav8]

I'm still confused - in a couple of your posts you say P3D setting VSYNC= ON and the last post you say OFF and don't mention triple buffering.
Thanks for all the info and I will try it. If Vsync is OFF -( BTW, what are your settings with NV Control Panel), is there any real "sync". I don't see why the monitor refresh rate (63Hz) has anything to do with it then.

Thanks

Dave

[pabloa2]

(Edited out offensive content)

NVIDIA Inspector

Frame Limiter - 31.5
Performance Mode - Maximum Performance
Trilinear Optimization - Off
Transparency Multisampling - 2x Sparse grid supersampling anti-aliasing

Custom Monitor Resolution

1920x1080 @ 63 Hz

Prepar3D Settings

Graphics

Resolution - 1920x1080
FXAA - Off
MSAA - 2 Samples
Anisotropic Filtering - 16x
Texture Resolution - Ultra
VSync - Off
Target Frame Rate - Unlimited
Tesselation - On

Scenery

LOD Radius - Max
Tesselation Factor - Ultra
Mesh Resolution - 1m
Texture Resolution - 7cm
Land Detail Textures - On
Water Detail - High
Bathymetry - Off
Reflections - Default
Scenery Complexity - Extremely Dense
Autogen Vegetation Density - Very Dense
Autogen Building Density - Very Dense
Special Effects Detail - High
Special Effects Distance - High

Lighting

All Default except - SimObjects cast shadow checked

Weather

Cloud Draw Distance - 100 mi
Cloud Coverage Density - Maximum
Volumetric Fog - On
Detailed Clouds
Thermal Visualization - None
Rate at which weather changes over time - No change

Traffic

All zero except Airport Vehicle Density - Medium