GPU is not fully utilized (RTX 3070)

[cykacyka]

Alright so I have the RTX 3070 Ventus 2x (probably the worst edition of the 3070) and I underclocked it so it draws less power and won't get as hot as it got before. Anyway, most games are running fine, 95-99% on utilization almost all the time and no FPS drops, as it should be.
But whenever I decide to play on high traffic servers in Assetto, my utilization is usually around 50-60%, sometimes it reaches 99% but then quickly drops down to 50-60%, sometimes it sits around 30-40%. As you can guess, the impact of it on the FPS is really big, game runs at 30-50 fps when it really should be running at 70-80fps. A friend of mine plays on the same high traffic server with a 3080 (non ti) and he gets around 90-100, shouldn't I get around 60-80fps then?
Also don't think it's a CPU problem, I have the 3700x and most of the time it sits around 20-40% utilization. However, I did notice that the VRAM usage is getting to 8GB on that server, maybe that could be the issue? The 3080 has 10GB, mine has 8GB. Maybe that could be the reason, although I don't know for sure. I'm running latest csp and sol
By the way, if I lower the settings, the performance does not change, how weird is that.

 

[Lizard Of Bodom]

Alright so I have the RTX 3070 Ventus 2x (probably the worst edition of the 3070) and I underclocked it so it draws less power and won't get as hot as it got before. Anyway, most games are running fine, 95-99% on utilization almost all the time and no FPS drops, as it should be.
But whenever I decide to play on high traffic servers in Assetto, my utilization is usually around 50-60%, sometimes it reaches 99% but then quickly drops down to 50-60%, sometimes it sits around 30-40%. As you can guess, the impact of it on the FPS is really big, game runs at 30-50 fps when it really should be running at 70-80fps. A friend of mine plays on the same high traffic server with a 3080 (non ti) and he gets around 90-100, shouldn't I get around 60-80fps then?
Also don't think it's a CPU problem, I have the 3700x and most of the time it sits around 20-40% utilization. However, I did notice that the VRAM usage is getting to 8GB on that server, maybe that could be the issue? The 3080 has 10GB, mine has 8GB. Maybe that could be the reason, although I don't know for sure. I'm running latest csp and sol
By the way, if I lower the settings, the performance does not change, how weird is that.

You need to provide more info, what resolution you play and what settings you have on (video rendering settings, extra FX from CSP etc). Its possible you have something on that is causing weirg graphics behaviour, in my case for example sparks and tyre particles are causing immediate 50% utilisation drops and game become unplayable. Would suggest turning off most of CSP settings and start enabling them one-by-one until you pinpoint what is causing that.
also what tool you use to see utilisation? you are sure its the GPU util not CPU ?
What utilisation & FPS you are getting when running AC's benchmark tool?

just for comparison - on my ancient gtx980SLI setup I can still get playable 75fps on LAC traffic servers with medium graphic settings and lot of CSP goodies ON. Have the same 3700x as you but I play in 3xFHD resolution.

edit- just re-read your post, have you tried running AC with stock card setup? undervolting it may have caused some odd behaviour, get back to stock first before you try anything else and just confirm its not the root cause, then look for further solutions as I mentioned above.

 

[stigs2cousin]

AC is on an ancient engine and uses mostly only two threads.

So 40% CPU usage is already fairly high with the possibility of CPU choking.

I don"t know enough to suggest the right diagnostic tools, bit I think @RasmusP could help.

MFG Carsten

 

[RasmusP]

A friend of mine plays on the same high traffic server with a 3080 (non ti) and he gets around 90-100

What cpu and what ram speed/timings does your friend run?

Also don't think it's a CPU problem, I have the 3700x and most of the time it sits around 20-40% utilization.

It is most likely a cpu bottleneck. AC simply can't use more than 2-3 cores and at more than 5 cores you basically see no fps improvement at all anymore.
Imagine AC like hammering an endless long nail into a wall.
You need 2 hands.
Will a third hand make it quicker? Maybe for holding the nail in a different position or so.
Will 4 persons, 8 arms make it faster? Nope, they can only watch you hammering.

Windows will often switch the cores though. Basically one person hits the nail once, then the next person hits it once and so on.
Since Taskmanager refreshes at 1s and you have 4.000.000.000 cpu cycles or more per second, you'll only see an average of a few thousand cpu cycles per core.

So to get more fps in Assetto Corsa, you don't need more hands, you need a few faster people.

I don"t know enough to suggest the right diagnostic tools, bit I think @RasmusP could help.

Yep, it's pretty easy for AC, luckily:
I'll quote myself:

"
If you really want to know what's going on, you need to enable "developer apps" in content manager - Assetto corsa - apps.

Then go on track and search for the graphic stats and render stats apps.
The icons are different depending on your csp version and settings but you should find them. When active, they look like this:

The important values are:
- FT for frame time (ms between the single frames)
- Main_t for cpu single core usage
- CPU for the cpu frame time
- Diff for the difference in cpu frame time to actual frame time (basically cpu headroom)

And then also very important:
The blue and red line!
Blue = cpu frame time
Red = graphics card frame time

Whatever line is higher is the fps bottleneck"

CSP has its own/extended render stats with a lot more information afaik. I don't have it enabled though...

 

[Lizard Of Bodom]

....
Imagine AC like hammering an endless long nail into a wall.
...

LOL for this comparison, actually brilliant will shamelessly use in future

as for AC's internal apps - is any of values actually showing GPU utilisation in the form of afterburner GPU core percentage? Not sure if frame times (although valid info) can give the same info, I usually find GPU core utilisation+GPU core temp overlay from afb/rtuner as most valid tool to keep an eye of "what my gpu is doing now".

 

[RasmusP]

LOL for this comparison, actually brilliant will shamelessly use in future

Haha thanks! I came up with it after discussing a few days about all this stuff about 2 years ago iirc and didn't find a better comparison yet

as for AC's internal apps - is any of values actually showing GPU utilisation in the form of afterburner GPU core percentage? Not sure if frame times (although valid info) can give the same info, I usually find GPU core utilisation+GPU core temp overlay from afb/rtuner as most valid tool to keep an eye of "what my gpu is doing now".

No, not really. The render stats don't show any loads at all. The "main_T" isn't the load either, it's just how much percent of the overall cpu frame time, the main thread took.

I'm using afterburner + rtss overlay too. Great combo tool!

And yep, they don't show the same thing at all. The frame times are the result of what the cpu/gpu are doing (or the fps limiter (vsync)).

Afterburner can show the overall frame time after the gpu but the AC render stats show you the cpu time separately, which is very useful!

In case you or anyone wonders:
As far as my knowledge goes, one frame is always cached, so the frame times are not adding up!
If you're using an fps limiter at 60 fps (or vsync), that's 16.67ms frame time.
The cpu can take up to 16.67ms and the gpu too.
Only when one goes higher, the fps will drop.

A few games like battlefield 5 have a setting called "future frame rendering" and although I use gsync, so there are no frames buffered like with vsync, disabling that setting will result in massive stuttering!

I guess that setting makes the frame times add up so cpu and gpu both need to have the frame done before it's sent to the monitor.

But that's a bit of speculation...