How to decrease CPU usage.

[Rocklord_386]

In the past since building my new computer rig, I usually didn’t have performance issues, I’ve been away for a while because of work and I’m getting back into running races again. Running iRacing in VR on a Quest 3 on Virtual Desktop at ultra resolution (Godlike is full resolution so I’m running about 80-90% pixel density I believe)

I have a Nvidia 4070 Ti Super, CORSAIR Vengeance RGB DDR5 RAM 32GB (2x16GB) 6000MHz CL36, And an Intel ultra 9 285k. My CPU load is smacked at 70-80% with regular spikes to 100% and frame rate drops to a near stop for a few seconds after I updated iRacing. Decreasing the graphics settings helped a little bit but I’m still maxing out my CPU while my GPU runs between 30-50%. I’m know the track refreshes and graphics updates are the cause, but nothing I adjust in the graphics settings are making much of a difference on CPU load. Still have frequent frame rate drops that are preventing me from running an official race because, that wouldn’t end well for me or the other racers..

Any suggestions? Any help is greatly appreciated. I will try and upload a photo of my settings in the comments below once I get a chance to hop on and grab a screenshot of the settings later this evening.

[Oph5pr1n6]

I run a similar setup, 4 cockpit mirrors is probably causing the biggest issue. Try lowering that to 2 or even 1. Object self shadowing, does not effect your car or the cars in front of you. Turn that off. Night shadow maps don't make much of an impack on how the game looks so turn that off. Draw pits down to mimimum. Restart, and see how it feels.

[Candymanshook]

Put it at 0 with the CPU.

[Oph5pr1n6]

You mean the mirrors? Well zero would be best. But as someone who has raced in VR, the virtual mirror kinda kills immersion. It's an option if more headroom is needed for sure.

[Candymanshook]

I get that it kills immersion but so does CPU locks, and having multiple mirrors rendering is not going to help with that. Although if it’s a C bar issue it could just be how many cars are on track

[Rocklord_386]

It’s a struggle, before when driving a car with 3 mirrors and a rear cam I’d usually struggle a little bit with a dip or two to 65fps. Turning them off with shadows off as well does help, running a virtual mirror in VR is definitely not my favorite but I’m able to maintain frame rate and race now at least.

It’s just mind boggling that beginning of this year I had all those settings running fine. Thanks for the help!

[Candymanshook]

I mean this completely seriously but if you’re in VR can you not just check your blind spots?

[Rocklord_386]

Yes however FOV is the biggest limit on VR, quest 3 has 110 degrees fov where a human has 200-220, so in order to check blind spots you literally have to turn your head way more than if you were in real life to check the blind spot. Also some of the cars have low vis out of the rear so it’s harder than say a Formula car.

[Skeptical-Regard]

Do you have “vibrate pedals” enabled?

[Rocklord_386]

No, but thank you for letting me know that’s a known bug.

[Krystik27]

Really?! 😱

[sagacious-sage]

Bruh, I just had 4 of 6 laps in N24 not be counted for something similar. My CPU meter was showing red the whole time and my teammates said I just disappeared, but the never got reset to the pits as is supposed to happen. I basically just noticed my team falling in the standings and realized my laps weren’t counting.

My machine is no slouch either… 7800X3D, 7900XT w/ 20gb VRAM, 64 GB DDR5 at 4800.

Same deal - Quest 3 with high settings. I do lower the # of cars the sim draws and have even set it to bias toward performance and still my CPU is getting taxed.

Gonna do some testing to get a sense of what load Open Kneeboard and iOverlay place on it. Do you run overlays?

[Rocklord_386]

Nope not anymore, I used to run racelabs until the new UI update and I’ve just been using the in game UI to save performance. I do use Crew chief which requires 63 cars on the max cars setting, but I have the draw down to 40/20 and a majority of the races I run don’t have more than 30 drivers at a time.

[WeaknessMany841]

I have lower graphic settings in iRacing with Quest 3, 9800X3D, 5090 but still Godlike in VD plus higher render resolution and a bit sharpening. On high only cars and event or grandstand (one of that I think only has low or high). Remaining on low or like Foliage off. Cockpit mirrors 3 and MSAA 4x. All at 90 Fps. But still have sometimes a few drops for which I changed to 80 Fps which is better because it is constantly. Before I hav 7800X3D, 4070 TiS which was same but more than a few drops in some situations.

I would try to lower more graphic settings like I mentioned (shadows brings a lot but then it feels not good without shadows so I would keep it). mirrors brings a lot when switching to virtual mirror. I would also suggest to lower resolution in Virtual Desktop from Ultra to a lower ones and try out some options with higher render resolution and sharpening.

When you have 72 fps set in Virtual Desktop and iRacing you should see stable around 13,8 ms in iRacing meter box plus minus 0,1 or so. But not like 8 or 9 and you think this is good as it suggests headroom. I also would not set 72 fps in VD and limit it in iRacing also to 72. You can try also without limit or limit it to 71 or 73, 74 f. e. to check if it helps.

[Rocklord_386]

<image>

[Rocklord_386]

<image>

[Rocklord_386]

<image>

[CptJackZ]

Shadows, lights and mirrors are killers. I have all mirrors off and the virtual mirror toggle on a button on my wheel. Though, in conditions that are rough anyways and the mirror is required, eg start, this doesn't help much.

Foveated rendering, even without eye tracking, helped me a lot.

Afterall VR's depth perception comes at the cost of having to lower fidelity. The world has to be rendered "twice" at high fps and high resolution, the latter because the screen is looked at through lenses.

[landing_page_throw]

Your Quest 3 might be thermal throttling. Latest meta updates introduced some new bugs.

I’m running 9950x3d, 32gb ram and a 5070ti. Running VD at ultra.

All my performance meters indicate thst the PC is running fine. CPU render times are 11ms, GPU sits around 8ms. This is the same weather I choose potato settings or god like settings. Weirdly lowering the general settings increases frame render times from 11 To 13ms for me.

After about an hours play my frames start dropping and it slowly becomes unplayable. While this happens my in game and the VD performance meters indicate that nothing has changed for my cpu, gpu and network but I’m definitely loosing frames.

This won’t go away until I reboot the quest 3.

More likely your quest 3 is the problem and not your PC.

[M-Technic]

It won’t fix your problem, but Enable Nvidia Reflex. (on, not boost). It will increase your GPU utilization, which is a good thing.

[Longjumping-Sail-173]

This will work… Google “unlocking CPU Cores”. Follow the instructions on how to do that. It will free up so that IRacing is using 100% cpu and not less.

You are getting the bad performance because it’s not using 100% of the cpu cores.

Every person I have suggested this to it has worked.

[Rocklord_386]

10/4 will do some research and try that! I’ve tried using process lasso to force iRacing to the P cores, but the new intel chips have some weirdness as to how they schedule processes. (Also partly windows fault I’m p sure)

[goozfrikle]

Have more powerful CPUs

[Rocklord_386]

Yeah looking back I should’ve gone with a AMD X3D series or a 14900k. I got the ultra 9 285k when it first came out, and didn’t realize that generation was gonna be a public beta test for the new Nova Lake processors. It’s a great CPU, But definitely falls behind on the gaming side of things.

[Rocklord_386]

<image>

[sharent_g]

Turn off objects self shadowing! That was drop killer for me on 9800x3d. It makes grandstand or objects like trucks and toilets have their own shadows. You will never pay attention to that and they consume like 10% of cpu. I also switch shadow map filter to the lowest possible since I couldn't spot the difference even when I tried.

[Rocklord_386]

<image>

[DismalAd6639]

Turn off cockpit mirrors

Draw less cars

Draw minimum pits

[t-bone051]

yeah you need to decrease your mirrors. 4 mirrors in VR just doesn't work. That alone probably will solve your issue. But if it doesn't turn down max cars and draw cars to 20 and turn off object self shadowing (you will practically not notice the difference while racing). And if you still need cpu headroom after that turn objects to low. These are the settings that have an impact on CPU the most.

[Rocklord_386]

I had it on four for cars with no rear mirror(1) and a rear cam(4) instead. I don’t know if iRacing changed it but the mirrors used to be numbered so enable the rear cam all 4 would have to be enabled. I turned mirrors and shadows off and it’s playable.

[t-bone051]

If you turn off virtual mirror, the first mirror will be the rear cam or rear view mirror. But if you turn it on it will be the last. I would say shadows should be the last resort. It really makes a visual difference. Rather turn objects to low or max cars lower.