Dear @PIMAX-Support@pimax.li I read that you have created a special algorithm which takes away the ghosting within the IPS LCD panel of PIMAX 4K and that you even improved in the latest drivers / software updates.
I would love to hear more specifications / details about how this algorithm works, if possible.
Second question, I am hearing about the fact that PIPLAY 2.0 will be a massive improvement, would you include any-game-sbs feature? To allow PIPLAY run any PC game in SBS (side-by-side) mode? I believe this would be a great feature and a strong edge for the product, taking away the need to use 3rd party applications for this.
3rd question, could you please update us about your progress in creating the compression drivers / software to allow a native 4K @ 60 FPS Resolution with PIMAX 4K model? Why can’t you enable 4K @ 30 FPS already? HDMI 1.x should support 4K @ 30 FPS, isn’t it? Maybe certain utilization of DSR technology could help you accomplish it? https://www.geforce.com/hardware/technology/dsr/technology
OR Perhaps some use of this idea / technology?
Nvidia’s come up with an old, but doable workaround. Before the video stream is sent to the monitor, Nvidia cuts out unnecessary colour information to make the actual stream smaller in size, opening up enough bandwidth to fit in a 60Hz stream over the regular HDMI 1.4a interface. For most people, this shouldn’t affect their viewing of video or other online content because typically that extra colour information is chopped out anyway in the source video. The technique is called chroma subsampling and it’s been around for quite a while.
I can answer question 3. The particular display panel used by Pimax for the Pimax 4k is a panel from Sharp. It only has 2 datalanes. To handle 4k 60 hz it would need 4 datalanes. However Sharp bypassed this problem by enabling compression. The driver chip can handle Qualcomm FBC 2.0 and VESA DSC 1.1 compression, which is much like the Nvidia technology you posted. So the ‘only’ problem is to compress the HDMI feed with one of those 2 compressors If you can solve that problem then you’d have 4k native resolution.
The latest generation videocards do support VESA DSC 1.2 compression which is 100% backwards compatible with DSC 1.1 compression but only over Display port. I’m not sure it’s even possible over HDMI. I’ve asked @PIMAX-Support a while back but never gotten any answer. I think we might be f*cked and that it’s just not possible over HDMI. I’ve never found an 100% conclusive answer on the internet but I think HDMI 1.x just doesn’t allow for compression.
Oh well, the Pimax 8k should be out in a few months anyway Pimax already said that native resolution will be possible on the 8k.
My theory is this: the chip in the Pimax that decodes the HDMI info is just a generic chip. This means that it expects 100% HDMI protocol conform data. If you’re going to compress it you’d probably mess up meta data. So I don’t think it’s possible to send compressed data over HDMI 1.4. And that’s probably why Pimax stays silent because they’ve realized it too.
I might be wrong though, it’s just my current theory
Nope. HDMI 1.4 has bandwith for 4096×2160 at 24 Hz or 3840×2160 (Ultra HD) at 24 Hz/25 Hz/30 Hz. So you’d say that at least 4k @ 30 hz would be possible, right ? But the panel can only do 60 hz and then the problem with only 2 data lanes to the panel remains: even if you’d send 30 hz via the HDMI cable to the HMD with the idea to just send each frame twice to the panel, then the problem is that you’d still need 4 datalanes to send 60 hz.
I think Pimax chose HDMI 1.4 because they thought that higher bandwidth from for example DP wouldn’t matter because of the 2 datalanes bottleneck. But if they had chosen DP 1.4 then we’d have DSC 1.2 compression which is 100% backwards with DSC 1.1 so in that case it would have worked.
My guess is that the Pimax 8k comes with 2x DP 1.4 for exactly that reason. Then again they might also refrain from compression at all if they really can get OLED panels with 4 datalanes. In that case they might go for 2x DP 1.2 or 2x HDMI 2.0
I think you’re right. I was reading this discussion and they say too that 2x4 lanes should be enough for 4k@60hz uncompressed ! So in that case the HDMI 1.4 connect indeed is the bottle neck. We should be able to get 4k @ 23/30 hz uncompressed over HDMI 1.4.