@Matthew.Xu said that 5K has better refresh rate (did he mean fps?) Than 8k. How much better exactly? How many percent better?
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Both 8k and 5k use 2*1440p in the game
As you know, Refresh rate restricts Resolution each other, FPS depends on your GPU performance, we are still optimizing it and will share more details soon.
From our current test. 5K has passed the initial stability test, but 8K is fail.
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ahh, so the issue is locked in to the scaler in the 8k,
does that mean 5k will display stable 90Hz?
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We are not sure now, still need do more optimizations and verifcations
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Looks like. Considering that both use the same panels, we can rule out the display itself.
That makes no sense, the 5k uses 1440p panels and the 8k uses 4k panels, the difference is the 8k upscales the 1440 to 4k.
Actually you are right. The 5K is less demanding as far as rendering is concerned. The 8K and 8K-X use the same panel. Got a bit confused there.
The 5k and 8k are exactly the same in terms of how demanding they are on your computer.
Read this for more info:
http://community.openmr.ai/t/settled-for-5k-here-are-the-reasons-why/4059
I have been voraciously reading up on this project for the last three days and have found some conflicting information on the forums…
I think I have this right:
In terms of hardware demands, both the 5k and 8k (not X) use 2 x 1440p input signal… In the case of the 5k, that is displayed directly on the two screens and upscaled to 2160p for the 8k(not X).
2 x 1440p @ 90 FPS is within the bandwidth limit of a single DisplayPort 1.4 link without using compression (which NVIDIA cards do not offer).
There seems to be a problem that the 8k is not stable at 85FPS+
The X is different and can accept two native 4k streams @ 90 FPS. This is beyond DP 1.4 raw stream spec and would require two DP cables…
I wonder if that one is stable @ 85+
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Is there a workaround? Next gen GPU’s?
no. its not a question of horse power driving the water down the hose, its a question of the maximum flow rate of the hose. Basically, the components being used have a theoretical maximum of 90 hz in this application. The reality is its probably impossible to hit 90 hz and they will land between 82 (whats currently stable) and 90
However between asynchronous timewarp/spawewarp / brainwarp its probably going to be buttery smooth anyway.
Seems to me you have that right. However, per a post Pimax made regarding the DisplayPort bridge chip, it isn’t fast enough for 3840x2160 at 90Hz due to a pixel clock limit (720MHz, whereas that mode would require at theoretical minimum of 746.5MHz). So it’s still a bit unclear how fast the 8K X will be able to run; that limit would suggest 86Hz refresh rate, while standard CVT-R2 timings produce only 80Hz. If we cut horizontal resolution to 88% we might hit 90Hz (a trick that may combine well with the mechanical IPD adjustment).
I have a theory how they can achieve 90Hz at native res on 8K X, it is confirmed that KS version will not have scaler to allow lower resolution to save bandwidth from GPU to HMD. DSC compression sounds like only option, I found it was already discussed for 4K version, but probably upscaler can’t support it, since it is very simple logic it performs, can’t handle compression logic(my understanding), FPGA can handle compression logic.
That can explain why 8K X is delayed comparing to 8K, and cost +200$ .
About 8K at start of KS it was noted there will be option to provide 2 input resolutions, 5120x1440 and 5120x1080. At 5120x1080 my theory 8K will run at 90Hz, at 5120x1440 75-82Hz .
And there is no need to use DP1.4, DP1.2 speeds will allow this solution. Will picture quality suffer from 1080 vertical resolution doubled to 2160 - probably. That is why it is not noted anywhere yet as final solution to “Hz-Gate” 
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EDIT: ANX7530 has a DSC engine, so no need for special FPGA, DSC is not used with 1xDP because every Display needs 2-4 slices, so with 1DP solution and 2 Displays DSC can’t work source
EDIT2: DSC is for MIPI port not DP port as input, so with ANX7530 this is not an option. Some other chip, maybe…