Tobii Transport Codec. Will it get us there?

There was much discussion previously about whether the Reality 12K could do 6Kx2x200Hz and the answer via Pimax and forums was primarily: “maybe with Tobii Transport Codec, but not RAW via a single DP1.4 cable.”

I pose the following:

Will it have significant latency?

Will it we want to turn it off and have the RAW stream due to visual artifacts?

Will they bottleneck the 12K with a single DP1.4 cable, use 2x1.4 cables, or can they utilize DP 2.0 in some way?

Kevin touched on these ideas and the answers were kind of “yes, we’ll see…trust Tobii”, but I wanted to poll thoughts from others and just see what people thought on one thread.

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That is not accurate. Pimax has said that it could do 6K per eye, and it has said that it can do 200Hz. The original presentation specifically said it couldn’t do both at the same time. And that was restated again in the recent interview. It’s going to be like the 5K Super where the max frame rate limit drops as FOV increases. During the interview, he said it would get 90Hz at the full 6K though. But his tone sounded to me like that’s going to be about the limit for full res.

I can’t think of any engineering reason why it would. I think it’s just a different binary format for packing the raster frame which avoids unnecessary repeating of data in the foveated rendering use case.

As long as eye tracking is working correctly, probably not. Presumably there will be some special cases where you’ll end up wanting to turn it off because of some rendering anomaly or bug, but it will represent a big performance hit to do so. Kind of like you don’t turn parallel projection unless you have to.

My guess is that they’ll go with a single DP1.4 cable. And then later they’ll do some model refresh that upgrades it to DP2.0.

Dual DP1.4 cables would stop the transport from being a bottleneck, but the greater resolutions that would allow are generally beyond the ability of GPU’s to keep up with anyway. So I think if Pimax went dual DP1.4’s, they’d get into a lot of support headaches (because it would be a rare configuration perhaps not well supported by GPUs) for little meaningful gain.

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Until pimax can demonstrate these features all we can do is speculate; as so far it is only bling updates on what is coming.

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I just watchted @PimaxUSA’s interview with @mixedrealityTV yesterday and he stated quite clearly, that the 12K will come with two DP1.4 cables. I expect a setup exactly like in the Varjo VR-3.

I didn’t say that. I said we have multiple test devices with different interface configs being tested.

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It seems to me like there’s a lot of factors to consider there without a clear obvious choice for the best one. One major factor would be compatibility. Which way works for the most people with the least support headache? 90Hz native has been problematic on the 8KX, and I’m sure Pimax doesn’t want a repeat of those kinds of issues.

The other biggest consideration of the choice would be the 40 series nVidia cards. Just how powerful will they really be? If you were only considering 30 series cards, I think single DP1.4 is probably the obvious choice. But maybe the 40s can drive enough pixel rate that a single DP1.4 would be a significant bottleneck (versus oversampling). But even if they can, how available are they going to be? And really needing dual DP1.4’s would probably only be a factor for the top end cards in the line which are going to be very expensive and also require whoppingly big power supplies and cooling.

Pimax really needs their new Reality series to have significant market penetration in order to support game developers adopting it and not just for a very narrow market of customers who have the most expensive and hard to get hardware. But they’ll also want the 12K to be the “go to” premier VR headset for that top end, too.

And then there’s DP2.0. That’s expected to appear on the 40 series cards. And it could run as DP1.4 on 30 series cards. That could be a great choice since the 30 series cards don’t push enough pixels to really need dual DP1.4 anyway. And the only GPUs that would be able to push so many pixels also have DP2.0 capability. But the availability and maturity of DP2.0 hardware to put into the 12K might be a problem.

That seems like a lot to consider. And a lot of it requires difficult predictions of the future. It would make sense for Pimax to delay the final decision as long as they can because that future gets easier to predict as it gets closer. Especially revelations about the 40 series.

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That makes a lot of sense. I need guys like you to keep me grounded in reality. Kevin was clear and I remember that now (apologies @PimaxUSA it was a long interview.) I guess I was hoping for some kind of: “it takes two DP1.4 spots on your 3090 video card but it’s seemless and connects to our HMD as if it were one DP2.0.” Maybe it was HDMI or DVI, but I do remember the first 4k monitors with 60hz did something like that to get the bandwidth needed. In any case, nearly everyone has two or three DP ports on their cards I thought? My 3090 has 3.

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To some extent the wildcard seems to be Tobii tranport codec. Do you agree? I mean if the bandwidth was the same as the 8KX, which was maxxed out, improvements such as lenses and FOV are nerfed! I mean it would just be a darn shame to have new displays, new lenses, wider FOV, if I cant DRIVE the display. It would be a discredit to all Pimaxs other innovations if it wasnt a good interface and bandwidth. What if I bought an 8k TV and it had one DP 1.4a input (maybe not a good example since this is 12k). The lenses may be better. FOV just spreads it out. This aspect would lend itself VERY well to a cheaper version. Call it the “12K Lite” for the time being. In the end, I’m starting to feel like its the most important factor to me and the TTC sounds like a big dice roll. Without being crass: I dont want a gimped 12K.

I think it is just too early to be fretting over a final spec requirement til we are close to actual release. We still haven’t had even a simple demo of basic features. So atm anything is premature speculation based on a couple of non demo presentations of info. Bling hype.

Once they can produce the demo originally promised for Ces/just after Ces we will have some substance to talk about. Too much hypothetical without demonstrated substance.

Not to be a stick in the mud; but reminds me of all the hype of the canceled wireless module for our current pimax headsets that was said to be working well in testing.

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No I appreciate the grounded approach. I wasn’t around for the pre-8k hype and delays. I hope it is as Kevin said. With the world recovering, partnerships, off-the-shelf stuff, step-wise improvements. Either A: @PimaxUSA is a VERY good optimist and a darn good PR guy. Or B were about to be treated to the best thing you can put on your head!

I think if @pimaxusa is an Honest Enthusiast he can at least share in my desire to see the 12K have wider visual throughput in some form, whether it be by way of Tobii or wider bandwidth.

Let’s all wish him and his team well!


Sticknthemud.

Ok, I must have misunderstood. Thanks for clarifying.

Just rewatched. You did say that this sample uses two DP 1.4 cables but that you are being told that there are some single cable solutions and that the interface is something that is evolving.

Again, my bad for misquoting you.

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