False CPU reading in benchmark!?

[Rogerbee]

I was benchmarking Assetto Corsa to see what different settings did. I had things like MSAA and anisotropic filtering turned on and I had multithreaded loading turned on. With all these on, I was getting an FPS of 53 tops and CPU read 83. I turned all of them off and my FPS went up to 60, but, my CPU went up to 93! Why? What could have been causing that much load!?

My PC is this:

AMD FX6300 6 core
Asus Strix GTX960 4gb
1366 x768 monitor with 60hz refresh
16gb RAM

To complicate things, I opened task manager when the benchmark was running and it reported CPU usage of only 40%.

What do I believe!? Is the benchmark giving false readings?

This guy has the same processor and graphics card as me and I set my settings like his as much as I could. His resolution is what mine will be when I get my new monitor. Currently I'm at 1366x768 with a 60hz refresh rate.

Why are his CPU readings a lot less when we have the same CPU and graphics card!?

I'd love to know what is happening here.

 

[Rogerbee]

I will also add that I scrolled up and down task manager and nothing else was causing any excess load.

 

[Rogerbee]

Ok, interesting,

This is with multithreaded loading on, anisotropic to 16x

Anisotropic 8x multithreaded on:

Looks like I don't have to be as scared of my CPU as that benchmark made it appear.

What has anyone else experienced!?

 

[Johnr777]

Could it be that the reading you get inside AC is from one core? Task manager gives you an average of all 4? But I’m not an expert on this at all, lol

Also, the odds of you and someone else getting the same readings are slim to none, tons of factors can change the performance of the game... AI, types of mods, co-pilot apps, different tracks, and now the patch and SOL with their intricate settings and all.

Are you using AC’s benchmark, the one with Spa ?

 

[Pawel Ziolkowski]

I was getting an FPS of 53 tops and CPU read 83. I turned all of them off and my FPS went up to 60, but, my CPU went up to 93! Why? What could have been causing that much load!?

83*60/53=93 If you reduce graphics quality, each frame will take less time to compleate therefore CPU has less time to finish it's work. This just means that you are GPU bound.

AFAIR the "CPU" in AC benchmark is not "load" but main thread time. a 100% means the time it took to make the frame for GPU was the same as finishing that frame in main thread of the CPU, less than that means CPU is waiting for GPU to finish, more and you get CPU warnings and physical slowdown of the game.
Windows on the other hand shows is utilization of the whole CPU. On your CPU, in a single thread you might be maxed but windows will merrily show only 17% load distributed equally along all cores which is quite misleading. So the AC value is more important, thou why exactly it's high or low on similar specs, im not sure.**

As for anisotropic filtering - i think it relies heavily on the hardware of the GPU, if it's supported up to 16x, the difference between 4/8/and 16 should be nearly unnoticeable.


edit: ** - Are you using SOL / shader patches? Comparing benchmarks on my PC from before and after getting SOL CPU was 65% and now goes up to 90%. Also python apps themselves put a pressure on CPU, some even when are not on screen - just loaded. If you have too many apps it should drive the CPU usage up.

 

[Rogerbee]

Thanks for clearing that up. The game feels smoother and I get better FPS with MSAA off and Anisotropic at 8x. Yes, I am using SOL and the shader patches. I got a bit paranoid after a dud bluetooth adapter mucked things up when I wanted to set my Dualshock 4 up and I messed up the positioning of my network adapter so I lost the good wifi signal. I was waiting for something else to go wrong and got very worried it might when I saw the CPU figures.

I'll see where I am when I get my new monitor tomorrow and just be happy it works without chasing FPS that aren't there with the benchmark.

 

[Rogerbee]

I was thinking,

When I first built this PC, I hadn't actually intended it to be a gaming platform. I initially built it for 3D art. The software was Daz Studio and the 3Delight render engine that it used would mainly have the CPU do most of the work. Then they changed to NVidia iRay and that engine, with the right GPU, would have it do the work and not the CPU.

Right now, the GPU is being limited a bit by the resolution and capabilities of my monitor which is a 1366x768 TFT panel. Is the CPU kicking in to compensate? Once I get my new monitor, later today, which is a 1080 TN panel with a resolution of 1920x1080, the card will be able to work with it's capabilities, so perhaps the CPU might not need to do as much?

 

[Peter Boese]

Imo a bench with a race setup would be much better. Maybe 24 cars. Same type same car. The AC bench is a played replay, so CPU is not that stressed like when they are calculated.

 

[Rogerbee]

I see, how do you switch benches?

I would love to test AC on this new monitor, but, there's an issue I want to try and clear up first. I bought the monitor because I could get a 75hz refresh rate with a display port connection. When the PC boots, the monitor goes into standby and only comes on when Windows loads. It's a common issue with display port connections and NVidia cards and so far NVidia haven't provided a definitive explanation or a solution. There's a forum thread on NVidia with replies from within the last few days going back years, I even found a post from when I first got the graphics card! No solution suggested on there has worked.

I've approached AOC, the monitor manufacturer, for their take and will see what they say. I just want to game, but, I daren't if there's an issue waiting for me when I do.

SO frustrating!

 

[Johnr777]

I’m on display port and nvidia setup and the monitor works right away when I boot up the PC.

Mind you it runs at 60hz... maybe your current bios doesn’t support 75hz?

 

[Pawel Ziolkowski]

Display port, LOL man i feel your pain , it's complete trash, I'm using triple screens so i HAVE to use one and it has given me sooo much issues it's mindboggling, and yeah fixes are sometimes non existent as Microsoft blames Nvidia and vice versa and nothing gets solved... some people even made 50$ >hardware< solutions to a software problem. Ahh i need to stop or it's going to be a page long rant.

@Johnr777 i haven't heard about bios not supporting 75hz, analog displays 20years ago had no problems running 200+hz, but I could see it being a problem on a driver level for DP's digital one.
edit: Ah, unless you meant GPU bios, then maybe~~

@Rogerbee i bet your monitor has other ports, so try DVI or even HDMI, analog connection should not care at all about refreshrate.
PS: what windows u are using 10 or maybe 7/8?

 

[Rogerbee]

Using Windows 10. I fixed it by unplugging the HDMI from the graphics card. So, bye bye dual screen! The only other ports on the monitor are an HDMI and VGA. If I use HDMI then I'll never be able to use dual screen again even if there was a fix, and I'm not hanging an adapter out of the back of the DVI port on the card so I can use VGA. I didn't buy a monitor like this to use VGA, that's like buying a 4K TV and only watching black and white movies on it!

Another thing I've found are 1 stuck pixel and 2 dead ones. That's below the minimum before the manufacturer will let me return the monitor. You can only see the dead ones against a white background, like on this site and the stuck one is visible on a black background, which is what my desktop wallpaper largely is.

After the issues with my Dualshock 4 and the dud bluetooth adapter, the screen burn that led me to replace my old monitor with this one, high CPU load and now display port issues and pixels, I'm beginning to think someone up there doesn't like me!

 

[Pawel Ziolkowski]

I didn't buy a monitor like this to use VGA, that's like buying a 4K TV and only watching black and white movies on it!

Haha theoretical specs of VGA are actually higher than HDMI 1.x btw... (thou practically it has limitations, still 1920x1080@60 shouldn't be a problem. Heck i'm running a bit smaller TN panel at 75Hz on VGA cable as i type it

 

[Rogerbee]

With high quality settings in 1920x1080 with 75hz I can only get the fps up to 35.6, but, the CPU load is significantly less. Film speed is 24fps, so really I should be happy with that. I can see everything and the cars are still fast. Why do gamers want frame rates above the normal persistence of vision anyway!?

 

[Pawel Ziolkowski]

Why do gamers want frame rates above the normal persistence of vision anyway!?

1) Latency: 24fps = it takes 42 ms to complete one frame. Whats important for races is visually determining changes of speed of points on the screen. That means at least 3-5 frames in theory, but in practice it can be much more, so at low fps your response to (car) movement could be timed in significant parts of a second, and that's just slow.

2) Speed of movement: When doing a corner at 100km/h in GT car, and having close to realistic filed of view, the speed of some landmarks on screen can reach (for example) 60pixels per frame on 24fps, if a landmark is tall like a pole - lets say 10pixels wide, it means you are looking at such a slide show that fixing your eye on it becomes really hard, reducing both speed and accuracy of using it as a frame of reference.
Even at 60fps such landmark would travel 2 times it's width each frame. So if you'd focus on it you could still clearly see individual frames.

3) For cinema frames blurred together making it easier on the eyes, but on raw synthetic footage, individual frames are easier to pick up.
Human vision is very complicated system that has it's own post processing. The 24 film speed is just the minimum speed at which our brain smooths visual input enough to trick itself that movement is continuous (to reduce strain on itself). But speed/time accuracy of such vision is crap.

4)For the reasons above focusing on a low fps synthetic footage will tire your eyes a lot faster.

5) (Not visual but important) FFB, at framerates below 50 most wheels should start to experience a noticeable change in force feedback and the lower you go from there the more it feels like molasses.

Personally 100fps is good enough for me. Thou i'd still wish side screens had like 500Hz - to admire track builders's work .

With high quality settings in 1920x1080 with 75hz I can only get the fps up to 35.6

That's really low, i think 960 should be able to do much better, either you put some setting way too high (like reflections), or it's a driver issue.

 

[Rogerbee]

The main problem I had when I changed settings to raise the fps was very high CPU load. I've got it where there is lower CPU load and it looks and feels smooth. That will do me. Until I build an uber gaming rig, what I have will be just fine for me.

At the end of the day, if you're happy with it, stick with it.

 

[Rogerbee]

Hmmm, I found something else, and it could have a bearing on things.

I was getting choppy audio, and our very own Fonsecker was reporting the self same issue in a YouTube video. Someone mentioned the NVidia drivers, and a light went on! I'd downloaded and installed a new driver from my card manufacturer! DOH! You should never do that! It may not be compatible with your build of Windows! I remembered then where I got my last one from and the build number of the last good driver and am downloading the last good build of that from Guru3D. They are THE go to for Nvidia drivers.

It could also explain the dramatic FPS drop. I'll install it and let you know how I go.

 

[StefanoCasillo]

With high quality settings in 1920x1080 with 75hz I can only get the fps up to 35.6, but, the CPU load is significantly less. Film speed is 24fps, so really I should be happy with that. I can see everything and the cars are still fast. Why do gamers want frame rates above the normal persistence of vision anyway!?

why would you want to decrease your CPU workload?
The ideal value to shoot for in this case is probably 100% because that indicates a perfect balance between GPU and CPU workload.

 

[Rogerbee]

So, you're saying that it won't harm the CPU if I do that then? If that's the case then ok, I'll adjust things back to where they were before I set this monitor up. I thought the high load was harming the CPU.

Anyhow, I fixed the audio choppiness by reverting to default audio settings in Windows and turning off the enhancements.

 

[Rogerbee]

Changed things back to where I used to have them and the FPS is back up. The reason why that guy in the video probably got his CPU values lower than me may have been because he wasn't using Content Manager and had default post processing on. Anyway, I'll leave it all alone now and just enjoy it!