Silence from SweViver

I guess not, I do remember him saying he had tried many extensions and none so far have worked. But I do remember it being stated that the cable required for the 8KX is complex and took work, so probably the extension would need an active repeater component or something like that, and therefore it’s another expensive custom option like the original cable, if even possible. I’m not familiar enough with video cable tech to know exactly.

But if it was truly just a 10 minute test and they have since said nothing more, then I bet there’s one or more issues and it’s not as simple as he suggested. As you said yourself, otherwise it would be in everyone’s interest to spend 10 minutes to confirm and say yes.

So, I’m still interpreting this as “There are still ongoing problems to overcome to deliver these features. Hopefully they’ll be available later, but it’s not guaranteed.”


I have alot of experience using hdmi extension cables with the Oculus Rift and the OG Vive. I tested many brands and lengths in my quest to extend these headsets. I found the same length from the same manufacturer could produce different results one working great and the other no image or distorted. What I’m getting at here is cable quality varies greatly testing any one cable is not conclusive.
I’m currently using this cable with the Valve Index and Pimax 5k+/8k and I expect it to work with the 8KX as well…


I use a 10 meter hdmi fibre optic cable with my 4k projector . It was the only way I could get 60 hz 10 bit 4k HDR to work . So it’s definitely worth a try .


I honestly think they didn’t even try it in those modes as they were too busy with other stuff and wanted to move on.

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I am not an expert on the DisplayPort, but from what I read about it I understood that there are different speeds each DP version supports (called HBR1, HBR2, HBR3, etc.). DP 1.2 runs at HBR2. This is what 5k+, 8k, and 8k+ uses and what is sufficient for them.

8k-X requires HBR3 and DP 1.4 (technically it was DP 1.3 which introduced HBR3 speed). We know from some leaked info that the DP bridge Pimax used in 5k+ and 8k does not support HBR3. If they use the same bridge in 8k+ (technically there is no need to change it) then there is no difference and 8k+ should behave the same.

In other words, extension cables which worked on 8k or 5k+ should work exactly the same, the wireless (if it ever worked) should work the same etc.

Now, what about 8k-X, which has to run (in its native mode) at HBR3 possibly with DSC as well? First consequence is you need a better cable, (HBR2 ~ 5 Gpbs, HBR3 ~ 8 Gbps), most likely shorter, with better shielding and better material overall.

This is the reason why Pimax cannot confirm any working extension (I am not sure they tried the fiber, but I would be very careful about claiming the fiber can solve it without testing it either, because the speed specs for the fiber bridges might not be up to the HBR3 specs either).

You may (and rightly so) assume that in the upscaler mode the bandwidth 8k-X requires is exactly the same as the one of all three previous headsets (basically QHD res), but it does not necessarily imply that the implemented DP transmission runs at the same configuration (i.e. HBR2 speed). I can imagine that there is handshake on DP interface happening, which tries to run at the highest possible speed (HBR3) and if it fails there is no fall-back solution implemented to try the slower speed as well.

I do not think that the control over which bitrate the DP uses is exposed via the normal OS API, but probably only through some proprietary graphics card driver interface and Pimax needs to implement it. Which probably they did not.

The other option could be to instruct 8k-X to “downgrade” its DP interface to HBR2 speed only, to force the host to switch as well, but this again looks like an additional feature which needs to be implemented.

So what you consider to be 10 minutes test could be several man-days work.


Maybe but on other occasions when Pimax go silent it’s because there’s a financial or technical obstacle, or they have decided to backtrack on a previous promise.

Eg I have had responses to queries about the 8KX, but at the same time when asking about shipping a MAS for a 5k+ pre-order, they never respond. I think there’s a reason why they don’t simply say “Yes we’re doing it we’ll be in touch soon” etc etc


The MAS isn’t ready. The pimax day 1 prototype was knocked up from hand cut foam. The Pimax day 2 prototype was just the housing with no sign of the foam. I’d say it’s a few months from mas production


Ah sure, sorry I wasn’t clear. Not asking when they are shipping it, but if they will fulfill their original promise to send a MAS to those who pre-ordered. AFAIK it was the only goal promised to pre-orderers.

And maybe they still will, but complete silence on that specific topic isn’t encouraging

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I don’t know about ten minutes! These cables are not created equal. Neither are graphics cards. And they are working at the limits of what’s feasible with the transfer tech. Plus other conditions will affect it - heat, humidity, etc. Pretty hard to say definitively in all conditions and once they have done everyone will jump down their throats when 30% edge cases don’t work in the Sahara with a 1$ 2 metre cable claiming they’ve ‘broken promises’.


It takes ten minutes to flip it into upscaled mode (doubt sweviver even tried it) but perhaps the other user is correct and they have to program in a handshake to step down in order to use any extension even in upscaled mode.


And, if I am not mistaken, they also mentioned that they where „working“ with NVIDIA to get the juice out of the link from the graphics cards at the needed bandwidth and speed - sounded to me that event the cards are not plug n play at that level.


What do you use for connecting the optical cable to the headset cable?

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But then doesn’t the coupler have to up to the same standards?

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They make active couplers if needed, however with index and 8k/5k+, passive works fine.

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thank you, that specific version doesn’t seem to on on amazon uk, but they look like a generic thing so i guess i can just grab any brand.

Couplers don’t work with reverb ,maybe active ones could