75/90Hz to 150/180Hz (Brainwarp) How?

Hello all future Pimax owners, and devs.

I don’t understand the stated refresh rate, used in the title [taken from your official site.].

If a monitor is 75/90Hz than, as I understand it, that is the physical limit of the screen/monitor/hardware running it - You could throw 1000 frames per second at a 90Hz screen but you’ll still only get 90FPS on that screen. You say that with ‘brainwarp’ the 75/90Hz screens run at above their physical limits - 150/180Hz - How, exactly, are you doubling the refresh rate of each screen?

Have you, instead, offset the two screens physically controlled refresh rate, so that while one is in between displaying [one of it’s 90] frames, the other is currently displaying [one of its 90] frames? If that’s the case, they’re still running at 90Hz - just offset to run unilaterally - not running at 150/180Hz as claimed.

Additionally, can 90Hz/FPS be displayed on both screens, at the same time, so that the 90 frames are synchronized?

Thanks in advance to anyone that can help me understand

Frame interpolation to always maintain the displays refresh rate.

If you see a Sony TV that is marketed as 240hz its not, thats just marketing for frame interpolation.

Brainwarp is the Pimax version of ATW ASW with its own unique abilities.

Brainwarp displays 1 image to 1 eye at a time sequentially.


X= displayed image.
1 eye sees an image the other sees nothing. This is similar to active shudder 3d glasses.

This causes the brain to see more frames as the refresh of the displays add together.

At least thats a basic idea on the concept.

With Brainwarp off then your only getting 75 to 90hz.

Thanks for the replies people, I appreciate the help and your patience.

If it’s displaying one eye at a time while the other is off, both running at 90Hz, wouldn’t that mean it’s effectively halving the Hz/Framerate - not doubling it? I understand it’s their version of ATW/ASW - but both of those run at 45FPS when in use, still at 90Hz, not double the Hz as said here.

I think that’s the bit I can’t grasp just yet, how the “150/180Hz” comes into it when what’s described it actually dropping frames overall.

The displays are just partially out of sync.

A completed frame is image plus blank then blank plus image.

Think of it if it takes 10ms to display 1 image per panel if we offset the displays a bit say 5ms off.

Example left display will show an image at the following times 10ms 20ms 30ms etc

The right panel displays image at 15ms 25ms 35ms etc

This as i understand it tricks the brain into perceiving double the frames. The blank part of the image your brain fills in with the info from the eye that sees.

In theory this should work well. Think of the old viewmaster with the negative wheel of pictures. Ususlly there is say a scene that has a 3d effect showing the sun for example. If you close one eye the sun disappears close the other and the sun is there. With both it creates the ilusion of 3d as you brain combines the 2 images.

Now with the panels each running 75 to 90hz the the blanks will go unnoticed. Some folks might be sensitive to this effect which is why this can be disabled. In favour of pure frame rate so to speak.

In the end best to test to see which option works best for your experience.

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Thanks again,

So it works as described in my first post, with the two 90Hz panels being offset, both displaying 90FPS and there’s no actual ‘blank’ frame inserted or dropped - instead, that ‘blank’ frame is just the gap in between two consecutive frames on a single [90Hz/FPS] panel?

I think I’m up to speed, thanks for the confirmation.

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Your welcome. Your dead on as i understand the concept.

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Hey, sorry to revisit this. I was just thinking on the visual representation of Brainwarp on the main page:

If the image on the left (above) describes two 4K screens running at 90Hz, therefore each pink and blue image represent a single frame being displayed on each 4K, in sync, at the standard refresh rate of 90Hz/90FPS… Than the Image to the right (above) is in fact showing a halving of each 4K screens FPS to 45. The image shows no change in the timing, just dropped frames.

If what we were saying earlier is true, shouldn’t it look like this?

No. They have explained it like this: the panel they’re using is low persistence. This means is does not show a picture for the whole cycle, but more like half of the frame cycle So if you look at their picture, while L1 displays, L2 is in that ‘non display’ cycle and vice versa.

So what they do, both panels run at 90 hz but timed half a frame different. And then during each frametime, the panels display only half of the time and the other half of the frame time they’re off. That’s all.

Yes display/eye 1 and display/eye 2 run at half phase of each other, and I agree they should advertise it as “perceived 180 fps”. I cut them slack on that and the whole 8k thing because it’s only 8k total horizontally. It’s 8k by 2k I believe. It’s still an impressive hmd though.

The more important question you asked is how many actual RENDERED frames are being sent to the display vs how many are interpolated. We don’t know but it looks like it’s all performance dependent. They’ve personally told me they have ATW and ASW equivalents on top of brainwarp as well.
What is useful is that they offloaded interpolation off of the computer to a dedicated hardware processor in the hmd itself. So they have roughly four technologies in place to assist in performance, which is great in my opinion.


Isn’t that what my picture shows?

I’m talking specifically about the visual representation. In their example, the Timing hasn’t changed, it shows both examples running at 90Hz in sync, displaying frames at the same time on the left, and alternate frames on the right.

So, below:

Yes, it’s swapping fro one eye to the other, I get totally get that, but the visual representation would show that each single panel image would take twice as long to refresh - combining to give the impression of 90Hz/FPS. So that’s why I edited the image to actually offset the panels to swap from one to the other within the gap to give the impression of 180Hz.

How are you saying it’s not accurate? The way I depicted it has each 90Hz/FPS panel actually offset to represent the combined FPS/Hz to give the impression of 180 frames within a single 90Hz time frame

(Thanks everyone for participating, I am trying to understand it. I get how Brainwarp works now, I was just wondering about how its visually represented in these images)

Your last picture is right. Its 180hz

Technically 180hz will only be experienced where there is binocular overlap.
That last posted picture is incinuating each eye on the right would only be receiving 45fps though. Is that accurate?

Well we can truly blame StarBreeze of whom did that first in advertising StarVR 2qhd panels to give 210°Fov saying their is 5k panoramic vr.

If we were using desktop conventions then since we have a 32:9 perspective

5k should be Qhd Ultra Wide
8k should be Uhd or 4k Ultra Wide

But imo even this is not entirely true as there is the screen overlap.

Now as for is 200° fov possible? Yes come visit Canada & goto an IMax theater & you could try StarVR for yourself. Just realize you can’t buy one.

That’s what I’m saying… The descriptive/image on the pimax page tells us Brainwarp is running at 45FP per eye - It’s halved, not doubled - to give the impression of 90Hz/FPS.

8.3ms [90Hz per eye] frames becomes 16.6ms [per eye] frames - combined, in sequence, giving the illusion of 90FPS. That would make sense as to how they’re able to run a 4k image and have it appear a smooth 90FPS [45FPS per eye] across the 200° FOV

My image, the second one down, is edited to ACTUALLY offset the framerate to appear as 180 if two 90Hz panels were run at full speed, at the same time, with a staggered/sequenced frame rate. Your computer would still have to render 180 FPS at 4K in that scenario. It’s still 90 individual/different frames sent to each panel, while the other is not displaying an image. There’s no actual savings in computational cost unless it renders less frames per eye/panel somewhere.

All I’m saying is the specific image they’re explaining it with, to me shows Brainwarp being used to lower the performance cost by dropping frames on each eye to 45, and taking advantage of the two panel setup to appear as 90 [as opposed to showing it running at 180Hz/90 out of phase frames X2]

Isn’t that what it’s supposed to do?

I’ve edited heck out of this post. I’m driving, Sue me. :stuck_out_tongue:

I’m home now and realise I’ve just reworded and repeated myself 3 times :slight_smile:

Well they better offer a scenario where we can just use the screen offset, without doing the “always on reprojection” thing.
@deletedpimaxrep1 @PimaxSWD @PimaxVR @pimaxsupport

Not sure what you’re saying. In that last pic (the one on the right) the time interval is 180 hz (while the panels themselves run at 90 hz). This should give the illusion of full 180 hz, while the panels and game run only 90 hz. I doubt though it will give that 180 hz illusion but that’s what Pimax says.

No, they’re not dropping frames (at least I don’t think they are). I think they’re interpolating each 2nd frame. But Pimax doesn’t explain this, so who knows. I think this will only make sense if they interpolate each 2nd frame.

Ah yeah I missed the letters in your pic. I THINK it should be L1, R1, L2, R2 etc. Just dropping frames wouldnt make sense to me. But I get your point. I wish Pimax would clarify.

  1. for two 90hz displays in half step of each other that will only feel like 180hz if your looking at an area where both screens overlap visual information.

  2. unless each screen has slightly different information than the other, it will not feel like smoother motion. There are two ways that could work. A) the gpu renders 180 frames, b) it renders 90 but the interpolations creates new frames between rendered frames. The key point is as long as there is no repeated frames it should feel rather smooth in areas where both screens overlap/area of stereoscopic effect.