I have really great conspiracy theory, this will be fun, maybe not true, so I say now "This is only for entertainment purpose conspiracy theory lovers - enjoy"
I spend some time bashing my head, why use 2xHDMI on demo, when plan is 1xDP. So here is fun theory:
Laptop output DP 1.4 with DSC, DP to 2xHDMI adapter used, HMD accept 1440p@90Hz(DSC), per eye signal, give it to Driver IC, and here we go, we have answers about 90Hz issues with 1xDP input.
From BW requirements to send 1440p@90, this is sent as RAW, so can be DSC in my understanding. Or at least it needs to be possible, for conspiracy theory to work, or be fun at least.
Limits? Why bother with DP on HMD input? HDMI 1.4b when transferring 7.4Gbit/s length is limited to 2/3.5m as shown in demos. No room scale no fun?
Pimax acknowledged we can get more distance by using breakout box, so we use DP 1.4 into breakout, from breakout 2xHDMI 3.5m, still can be too low, so probably why they decide on DP or nothing.
This can also explain whole DP 1.4 marketing from start, we know ANX7530 is not real DP 1.4 only latter, original idea, 2xHDMI also needs DP 1.4, because DSC is part of DP 1.4, so yes HDMI and DSC, clever for sure, too bad cable is short. I feel bad for Demo persons, when they defend Laptop from person playing fruit ninja on 2m cable, hope is paid well.(can't find the video of it on YT, is really fun). And why use Laptop not desktop, well Laptop is to put it near user like with breakout box, same effect, only prob, some user may damage ~2000$ laptop, comparing to ~50$ box
I already suggested to Pimax when we thought that limit is HBR2 speed, to use b/o box, cause analogix say they support HBR2.5, to take advantege of that, they already had same idea I bet, I am no smarter than them... Or this also just theory, I actually am?
My idea was, make breakout box accept DP 1.3, output DP 1.25(HBR2.5), Pimax idea was out DP 1.4(DSC), send through 2xHDMI to HMD display 90Hz DSC image.
Had some fun reading? Am I only good at reading specs or also making(conspiracy) theories ?
Now for tech savvy, can claim "input is 4K upscaled to 8K" from FAQ be true? - Yes, yes it can:
3840x2160 is real input res, as they put in FAQ "4K(DSC 2:1) upscaled to 8K(4K per eye)".
3840x1080@90 DSC 2:1 through HDMI 1(Left eye), 8.34Gbit/s , cable limit is 10.2 Gbit/s(RAW)
3840x1080@90 DSC 2:1 through HDMI 2(Right eye),
Ouput from GPU is 3840x2160@90 DSC 2:1 . I made wrong assumption you need 3:1 DSC, my bad
EDIT: Hm, actually it was for sure compressed 4K, chroma subsampling not DSC, but that is going from conspiracy to real stuff. Need new post. I am not sure if DSC 1.1 is different from 4:2:0 I understand it also halves vertical res, and compress color data. Anyway, probably use GPU DSC encoder for this, hence the marketed "DP 1.4" even if used 2xHDMI 1.4b ...
3840x1080@90 (4:2:0) through HDMI 1(Left eye), now we calculate 18bit/pixel not 24bit, 6.26Gbit/s, can be 3.5m, I think.
3840x1080@90 (4:2:0) through HDMI 2(Right eye),