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Kaerar
23-09-2017, 14:20
Hi guys just ran a GT4 race in the BMW and noticed something slightly odd.

I have a 3930K running 3.8GHz and it hits an avg of 50% usage during pCARS2 operation. However the GPU is the interesting bit, it's floating between 60% and 80% usage. So there's no limit from CPU to GPU to bottleneck things as the CPU is floating around 40-60% on all cores (HT enabled). 32GB of RAM ensures space isn't an issue and game is on an SSHD (will move to SSD when on next build).

Really though the game should be hitting 95-100% usage assuming it's optimised properly otherwise it's just cycles going to waste. Oh running 1080p with a Vega64, most eyecandy on max without motionblur and only 4xMSAA. 60-80FPS is also interesting as well as I was expecting better numbers than that (though reflections could be at fault there...).

Here's the graph and it's really quite a mess of the activity going all over the place. The large dips in Mem speeds towards the end were when transitioning through menu's after the race.

240334

I am aware it could be poor optimisation on behalf of AMD's drivers for Vega64 which aren't exactly the best thing since sliced bread at the moment, however I am seeing much smoother performance in other gfx intensive games where the Activity stays pegged and the lines are much flatter than image above.

Kaerar
23-09-2017, 17:33
Here's a Unigine Superposition Benchmark run to compare from a Gfx load perspective (yes I know one's on rails and the other is dynamically reacting to user input).

240340

Aldo Zampatti
23-09-2017, 17:44
I would try a few things, but as a heavy AMD Benchmark guy on my past life (;)) I think I know the answer to this.

So first, Game Settings:
- Try replacing MSAA (turn it off) for Post AA: SMAA HIGH and add SuperSampling to Medium. That should work a bit faster on your card I think with (might be) better looking graphics
- Anisotropic 16x.
- Env Map & Reflections lower them down to Medium

With this settings, give it another try. It should work better.

Now onto the CPU, your 3930K is a 6core/12thread but on a older architecture (less IPC). Is a nice CPU but for gaming probably not the best. Project CARS2 simulates physics on the CPU and can split on different threads but of course has its limitations. For example: Each tire can be a separate thread (4 then is the max) so physics tyre can not be split in more than 4 cores. Then other tasks will take advantage for the extra cores but up until some point.

Hyperthreading normally makes your overall CPU from 15 to 25% faster (on average) than not having it, but not every App is capable of taking advantage of it because of the nature of what you're processing.

Try disabling HT in the BIOS and you'll see that your CPU time will be much closer to 100%. That will show you that you might be a bit CPU limited.

To workaround this, you can limit your FPS near 60 to avoid taxing the CPU too much with it will (of course) lower the GPU utilization too. I personally limit my frames a bit above my refresh rate since there's no point on pushing 100fps if your panel is 60hz.

Give this a go and report back, so you can take fully advantage of your GPU

B1rdy
23-09-2017, 17:47
Check load of each CPU core.

Kaerar
24-09-2017, 03:32
Will check the CPU usage and yes it was close to max minus HT (~50% with HT enabled) so likely some cpu limitation.

Kaerar
24-09-2017, 12:23
I would try a few things, but as a heavy AMD Benchmark guy on my past life (;)) I think I know the answer to this.

So first, Game Settings:
- Try replacing MSAA (turn it off) for Post AA: SMAA HIGH and add SuperSampling to Medium. That should work a bit faster on your card I think with (might be) better looking graphics
- Anisotropic 16x.
- Env Map & Reflections lower them down to Medium

With this settings, give it another try. It should work better.
That was enough to bring it to full GPU usage.


Now onto the CPU, your 3930K is a 6core/12thread but on a older architecture (less IPC). Is a nice CPU but for gaming probably not the best. Project CARS2 simulates physics on the CPU and can split on different threads but of course has its limitations. For example: Each tire can be a separate thread (4 then is the max) so physics tyre can not be split in more than 4 cores. Then other tasks will take advantage for the extra cores but up until some point.

Hyperthreading normally makes your overall CPU from 15 to 25% faster (on average) than not having it, but not every App is capable of taking advantage of it because of the nature of what you're processing.

Try disabling HT in the BIOS and you'll see that your CPU time will be much closer to 100%. That will show you that you might be a bit CPU limited.

To workaround this, you can limit your FPS near 60 to avoid taxing the CPU too much with it will (of course) lower the GPU utilization too. I personally limit my frames a bit above my refresh rate since there's no point on pushing 100fps if your panel is 60hz.

Give this a go and report back, so you can take fully advantage of your GPU
This CPU has very limited ability to change anything. I'm actually unable to disable HT in the BIOS, due to previous mobo causing some issues with the CPU. Has to run using Optimised defaults and RAM set to XMP only. Anything else = failed boot.

Next CPU should solve the issue nicely (16c 32t ThreadRipper :D ). So this situation is only temporary.

B1rdy
24-09-2017, 13:33
That was enough to bring it to full GPU usage.


This CPU has very limited ability to change anything. I'm actually unable to disable HT in the BIOS, due to previous mobo causing some issues with the CPU. Has to run using Optimised defaults and RAM set to XMP only. Anything else = failed boot.

Next CPU should solve the issue nicely (16c 32t ThreadRipper :D ). So this situation is only temporary.This game doesn't gain much performance of more than 12 threads.

Morgan Henstridge
24-09-2017, 13:39
That was enough to bring it to full GPU usage.


This CPU has very limited ability to change anything. I'm actually unable to disable HT in the BIOS, due to previous mobo causing some issues with the CPU. Has to run using Optimised defaults and RAM set to XMP only. Anything else = failed boot.

Next CPU should solve the issue nicely (16c 32t ThreadRipper :D ). So this situation is only temporary.

I went from a 3930K @ 4.5 to a stock Ryzen 1800X and the new CPU performs much better and using much less power :)

Kaerar
24-09-2017, 20:58
This game doesn't gain much performance of more than 12 threads.

Well aware, the ThreadRipper is for other purposes, gaming is a bit of a secondary but fun purpose for it :)


I went from a 3930K @ 4.5 to a stock Ryzen 1800X and the new CPU performs much better and using much less power :)

Yeah I know there's going to be a huge difference between my current 2012 CPU and the new HEDT on the block. Can't wait to get it into action.

As an aside I did a BIOS flash on my Vega64 from the stock BIOS (8730) to a newer Vega64 Liquid Cooled BIOS (8774) and the difference was very stark. Much smoother operation and able to stick to roughly 68C at 1582MHz with only 900mv instead of the previously needed 1050 to be stable there. More testing will definitely be had over the next few weeks :D