Will refreshrate OC be possible on Pimax 8K X if DP Fiber Optic cable is used instead?

Hey, got a small question:
So the specs say that if I am not going to use the upscaler, it is limited to 75Hz correct? I found that there are DisplayPort cables on the market which use FiberOptic. A friend of mine was using one of those and was able to overclock a 144Hz 4K monitor to around 160Hz or something. So if the DP cable is actually detachable, and we can use our own cable, then there would be (I guess) no problem if I just overclock the actual refresh rate and essentially get 120Hz with upscaler or ~80Hz without using upscaler.

What do you guys think? Those cables cost around $380 just for 3 meters and can easily be damaged/destroyed if bent or stepped on.However getting a couple more Hz, if you got the GPU and CPU power to drive them may be actually make it worthwhile investment?
I just hope that the new Nvidia/AMD high end cards will be less than $1K and be able to deliver the required performance so that the FPS can be locked to the refresh rate and not have any dips. Or maybe I will just have to start sub-zero cooling GPUs…

The cable on 5K+/5K XR/8K (current models out) is not a standard DP cable, but can be extended with a DP extender cable.

What You’re asking is if You can replace the original cable with a fiber optic cable and I’d say no as the part of the cable going from the headset to the “breakout box” is not a standard cable

It includes DP + USB + power in one cable and also a custom plug at the headset end and I’m guessing the new one will too (but we don’t know yet).

On another note, it does seem like the 8K+ / 8KX will be using a different cable as the specs/info on the current cable states:

*Compatible with Pimax 5K Plus/5K XR/Pimax 8K ONLY.


oh ok. I thought the USB and power and display are all separate cables and are all detachable. Oh well my bad. I would be fine with that though… I wish they would custom design a more expensive FO cable which would enable someone to push the Hz.


I think a lot of people would pay for that. Especially if it would mean it would also remove the 5m limit… :wink:

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It definately would, but FO wires can be damaged more easily than copper. I don’t know how would they find a way around that. It is worth paying for a FO display cable if you need more than 5 meters. I guess they have to introduce multiple lengths.

I’m using a DeLock 5m “4K/60Hz” extension cable and an active USB 3.0 extension cable with no issues on my 5K+, but it won’t work on the 8KX as far as I can understand.

They said in the Pimay Day 2 stream that they haven’t had any luck with extension cables on the 8KX yet… :frowning:

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The maximal refresh rate is determined by the lowest maximal refresh rate supported by each individual component in the chain:
GPU, cable, DP bridge, (scaler), panel.

Assuming the GPU is fine, you have still 4 other variables which might cause problems when you up the datarate, some may not even operate in the spec, some may not be overclockable at all.

On the side note: The cable used with Pimax 5k+/8k/8k+ is most likely DP 1.2 cable, because the headsets require only HBR2 datarate (DisplayPort - Wikipedia).

Pimax 8k-X requires HBR3 datarate, which requires higher quality cable (low impedance, better shielding, etc.). These cables are more expensive (because of the more expensive material/manufacturing) and also shorter, because even with the different material they can support HBR3 to only certain length. This the reason why FO is considered as a substitute (for long distances).

But in case of Pimax, I do not think the cable (alone) will be the major hurdle.

These days, we’ve been testing for Fiber optic. and will let you know the results. Currently, we just passed the testing for dual usb cables on 8KX. one usb cable is for both charging and transmission; and the other is for charging only and able to be plugged into a normal adapter.



Thanks. I just really do not wanna play on a VR headset below 100 FPS. I played on Oculus Quest and there was so much screen door effect. I want this to be totally gone and be smooth. I am surprised actually that I didn’t get motion sick. It was fun but at the same time it bothered me a lot (at least it was smooth enough though!).

For just that reason Id be willing to shell out a lot of cash for a cable and my system, if those were the problem. Have you tested if the 8KX headset can do higher Hz than just 90 at that 4K/eye resolution? I am pretty sure that if the 5K+ can do 120Hz, then the 8KX should also be able to and the only bottleneck would be cable bandwidth and current GPU capabilities.

I think if games are made to support dual GPUs, 1 highly OCed GPU/eye will be able to achieve 4K@120FPS. That would mean I’d have to buy 2 of the next best GPUs that will come out in 2020.

FPS (or maybe refresh rate/Hz) has nothing to do with SDE.

SDE is how much of the space between individual pixels You can see. That’s why many LCD panels (RGB sub pixel arrangement) have less SDE than many OLED panels (diamond/pentile pixel arrangement).

How did You come to this conclusion?

It’s, in part, the panels that sets the limit (that’s why apparently one version of 5K+ panels can while others can’t = different spec’ed panels).


So the new dual usb cables for the 8KX (that I believe you got in today) have passed have they? (I’m assuming they are dual USB as you say but the picture that Matthew posted today looked like it had 3 usb ports!)

Anyway, does this effect the expected shipment dates by any chance?

That looks like 2 Usb and 1 DP on one end, and the custom Interface on the HMD side.


I know. I want higher res to eliminate this SDE space between pixels, but also at higher FPS… Sorry you miss understood me there.

Yes panels have limits, and you can probably push them to those limits if you are not limited by anything else BUT the panel itself (monitors are overclockable). And the upscaler is one variable you can knock off from the bottlenecks if you don’t have one at all. The cable on the other hand - compression, perhaps size, or maybe some other “user convenience” must be kicked out for more bandwidth.

Exactly, well spotted. It’s Dual USB as shown.

Yes. It can always be adjusted though if the new cable passes testing more rapidly. At the moment though, the new projected 8K-X release date for backers is March/April 2020.

Previously it was December 18th 2019 for first batch shipment to 8K-X backers.

Although disappointing it would be more upsetting to find the special 8K-X cable was rushed to market and breaks.

Also I’m hoping new GPU’s surface May-October 2020 which 8K-X will need.

While it might be possible to overclock panel, it will not improve its response time. So you will likely end up with ghosting which was pretty bad in stereoscopic 3D and I assume even worse in VR (can’t really say as I did not notice any ghosting on 5k+ so far, but my 144Hz monitor definitely has some).

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You are not going to be seeing 144hz on a 4k panel. Lookup the availability of displays on the market currently, they just do not exist for VR.

DP1.4 to Optic converters exist but beyond the cost of most consumers. It would more than double the cost of the headset.