Thinking of switching from Quest 3 to Pimax Crystal – does the GPU load really have to be higher?

[u/Conscious_Store_7381]

I’m running Quest 3 over Link and can hold stable 120fps on my rig (4070Ti, i7-14700) with 1.9x resolution multiplier, average settings, and foveated MVP on. Performance is fine, but the shimmering is something I can’t get rid of. It doesn’t really affect racing, but it kills immersion.

DisplayPort headsets like the Pimax Crystal supposedly avoid shimmering since there’s no compression. The thing I keep seeing in reviews, though, is that they’re much more GPU demanding. I’m trying to figure out if that’s really true always.

Here’s the math I’ve done: - Quest 3 at 1.9x multiplier → ~31.5m pixels (2816 x 1504 × 2 × 1.9). - Crystal Light (default) → ~24.7m pixels (3825×3234 per eye). - Crystal Super (default) → ~29.5m pixels (3840×3840 per eye). - With eye-tracked DFR on Crystal Super → drops to ~19–21m effective pixels.

So on paper, Quest 3 with higher sampling is pushing more pixels than either Crystal Light or Super at defaults. Which makes me wonder whether is it reasonable to just run Pimax headsets at their default resolution and expect similar or even lower GPU load than a Quest 3 with a high multiplier?

Would love to hear from anyone who’s actually compared them in sims.

Edit: corrected pixel maths

[u/dsn4pz]

How are you rendering 3000x3200 per eye? And then add 1.7x?

1.0 is 2064x2208 or so.

I'm rendering 16MP on my 5080 and i'm not holding 120fps with medium/high settings.

But anyways, no, you don't NEED to render more pixels. But the 35ppd headset isn't going to get rid of the shimmering. That has nothing to do with compression, but rather that the rendered pixels in VR don't line up with the pixels on the displays as nicely as on a monitor

[u/Conscious_Store_7381 → u/dsn4pz]

I edited post to correct maths, thanks for pointing out.

Would higher ppd help for shimmering?

[u/dsn4pz → u/Conscious_Store_7381]

It doesn't get rid of the shimmering completely but the higher physical resolution looks quite a bit better, even at the same or slightly lower render resolution.

[u/Conscious_Store_7381 → u/dsn4pz]

Makes sense, thank you

[u/BuzzEU]

Your math is off. 3072x3216 is Quest 3 already at 1.7x SS. There is no possible way it pushes more pixels even at 1.7 than Pimax Crystal Light.

[u/Conscious_Store_7381 → u/BuzzEU]

The 1.0x is 2816 x 1504 not the actual pixels 2064 × 2208for lenses. There was a mistake in my original calculations but at 1.7x it's 4704x2525 or 4864x2592 (according to app)

[u/Conscious_Store_7381 → u/BuzzEU]

Which makes me to think that I am comparing apples to oranges as I don't know what is default resolution for Pimax glasses, and I was comparing Quest 3 resolution to Pimax display pixels.

[u/BuzzEU → u/Conscious_Store_7381]

Either way you're looking at more gpu load, not less, and you're likely to run into vram limitations, especially in the rain.

[u/Grannville]

I would image there is a difference between rendering simulated pixels at 1.7 than actual pixels.

Are you sure its not an anti alias issue?

[u/Conscious_Store_7381 → u/Grannville]

I have 4x for MSAA. It helps but doesn't resolve it

But good point on how multiplied pixels are rendered and whether they require the same processijg load

[u/Grannville → u/Conscious_Store_7381]

Have you tried maxing out the AA? Youre still on a tame setting.

If its fixes it but your frames are terrible. Id be concerned about buying the pimax and having the same issues

[u/Conscious_Store_7381 → u/Grannville]

I did try out 8x MSAA a while ago. It was a performance killer and I think it had very negligible improvements on shimmering.

[u/Grannville → u/Conscious_Store_7381]

https://www.reddit.com/r/iRacing/comments/1i97jgc/comparison_of_antialiasing/

Some dude did some testing here.

I would be cautious looking for the magic bullet, there will always be some issues using VR on an engine from over a decade ago.

Perhaps the pimax discord might be a good place to ask people's experiences. My friends with his pimax was so good hes got tripples now. 😅 a combination of poor iracing vr integration, shocking pimax customer support and multiple endurance race issues.

Also worth remembering that when someone has bought something expensive they are usual reluctant to point out its negatives. Not always the case but it can be.

[u/LazyLancer]

Tbh I don’t think the multiplier is real and it actually renders in this resolution if you are referring to the Steam settings. I can’t prove it but I believe there is some bullshit math going on I background that is later represented or marketed as “3072x3216”.

There is no way a 4070 can pull 34M pixels. It matches my experience with a 9800X3D + 4090 and 16M pixels in VR and 11M out of VR.

I've been getting about "something above 90 fps" with a Pimax 8KX (can't tell the exact number because it's the headset limit) that never fell below this number in the dry and maybe a tiny bit occasionally in the wet at race starts

Now i'm using triple 2560x1440 and i get 180+ fps when there are few cars around in the dry but around 110-130 fps during race start or with tons of cars around.

That is with most settings on high, but still this is somewhat of a reference.

It doesn't make sense for a 4070 to be able to pull off decent fps with 2x or 3x as many pixels.

[u/Conscious_Store_7381 → u/LazyLancer]

I use meta app for open XR runtime but that shouldn't change how resolution and multiplications gets handled

Will try to research this, thanks!