8kX - first impressions

Pimax Hardware P2: 8kX
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Yay, my 8kX came one day earlier than expected, shipping went smoothly, all good! (that customs number seems to have worked for me).
Here some initial impressions after some hours of experimentation. Will update this as new impressions become available.
My VR background: Have an original Vive and a 5k+, have been using the latter for the last year and am quite happy with it.

great (better than 5k+):

  • the added details in native mode are very obvious - looking really good!
  • almost no visible sde
  • better weight distibution
  • no “snow effects” experienced yet, even without special cable care (I sometimes see randowm white pixels with my 5k+, have to make sure that the cable isn’t close to any electromagnetic source - think my cable isn’t shielded too well. If this is ensured then the snow goes away on my 5k+ and all is ok. Not needed on the 8kX, works out of the box.)
  • ok, also a little room for improvement but definitely better than with the 5k+: still seeing noticable aliasing on straight lines, even in native mode (the resolution isn’t “retina” yet, so this probably has to be expected). But e.g. texts on Virtual Desktop are readable a lot better now. Not yet monitor level but quite usable. Higher supersampling settings can greatly reduce this effect. Don’t get usable framerates with these settings with my 1080 TI, but it’s good to know that the headset has potential upwards with a better GPU!

ok (like 5k+)

  • distortion is similar to the 5k+: noticable but imho not too disturbing - normal FoV is still the best setting for me. Perhaps dynamic correction via eye tracking can get rid of that at some point? Don’t know, don’t care too much either.
  • colors, contrast and brightness appear similar, neither better nor worse - thus ok. Edit: The 8kX seems to react well (better?) to contrast and brightness changes. Looks better than with default settings that way. Will have to check how the 5k+ would react to similar settings.
  • 75 Hz mode doesn’t disturb me e.g. in Alyx in a first test (I notice a difference in Eleven Table Tennis though - see below)

room for improvement:

  • noticably heavier than the 5k+ (but fortunately the better weight distribution somewhat helps there)
  • sweetspot appears slightly smaller than 5k+. But I can find a spot where the center is sharp for both eyes. Could be related to comfort kit. Or perhaps also to the added sharpness - you see much more of a difference between “almost sharp” and “really sharp” on the 8kX - as the 5k+ doesn’t have that level of sharpness, no matter how you adjust it, this might not be as obvious
  • 75 Hz is noticably less smooth for Eleven Table Tennis, prefering the 5k+ in 144 or 120 Hz for that game
  • 118 Hz upscaling mode has quite disturbing motionblur effects, would prefer the 75 Hz native mode for sports games when just having the 8kX. (Frametimes are far below critical levels)
  • in 118 Hz upscaling mode I see a copy of the screen content from the middle on the very left side. This also happens in Pimax Home (the thing with the Pimax logo) and does thus not appear to be SteamVR related. This happens no matter which FoV is selected. It looks like the left display isn’t happy with the timings.
    Does not appear in 75 Hz native mode.
  • noticable mura (particularly visible on white surfaces). Are there perhaps correction files similar to StarVR? Would probably have to be calibrated per device…
  • using the comfort kit for sports games leads to sweating much faster, lenses also start to steam up. A short break fixes this.
  • the on/off switch led doesn’t go blank when switching the headset off, it turns and stays red.
  • there seem to be two cases where the led is red: When the HMD is off and oddly sometimes also when it is kind of on. This “odd mode” can be identified with the combination of red led and active front light bar. For me when switching on my PC with the 8kX already being attached it is always in this mode. In that case PiServiceLauncher is driving the GPU to 100% load. Clicking the power button in that state switches it off (led stays red but GPU load goes down and front light bar switches off). Then pressing the button again will switch the HMD on again - this time the led will switch to green/purple and the HMD is fully operational.
    Particularly the fact that this “odd mode” is active when I start my PC - and that it leads to 100% GPU load is inconvenient. Thus the HMD has best to be plugged out after usage atm.
  • the speakers don’t sound particularly fantastic. I’m a little indifferent whether no speakers would have been better than these. On the one hand they can be better than nothing and are e.g. fully sufficient for the “tick” sound when the ball hits the bat in table tennis. On the other hand they unfortunately block my much better overear-headset that I have used with the 5k+ sometimes, when audio mattered. In ear would of course work. Perhaps they could put some plastic caps into the package that make the 8kX still look “complete” when removing the SMAS. Or make DMAS the default.

Additional observations:

  • Make sure to adjust the velo that goes over the head so that the counterweight can optimally take away weight from your face. Had this wrong initially.
  • Played with the contrast and brightness settings. Tried @SweViver’s proposed settings with brightness -2 and contrast +2. This worked well e.g. in movies (watched “fantastic beasts” with lots of contrasts). But it made texts harder to read. So as a default I settled on brightness -2, contrast 0 for now. But per-application overrides can definitely make sense.
  • for reading webpages it turned out more comfortable for me to use dark mode (e.g. via DarkReader). That way mura is also not visible. Found Virtual Desktop to be better at visualizing websites with text than BigScreen. BigScreen was cooler for movies though. That way one could also use different contrast settings for the different applications and scenarios.
  • watched a movie with the SMAS speakers now. This clearly isn’t made for music. But on the positive side text understandability is actually quite good.
  • Took me some time to get manual supersampling settings working: Manual settings in SteamVR didn’t have any effect on quality (nor performance) above ~110% supersampling, SteamVR applies a hardware dependent cap that ignores higher manual settings. Fortunately there is a good guide available for that now: https://community.openmr.ai/t/how-to-make-your-pimax-image-crisp/29688 . Shouldn’t be a hazzle anymore once Pimax Experience does this for us.
    Can set supersampling to 100-120% in SteamVR (for PiTool SS 1.0) with my 1080 TI. This is pretty close to the automatically detected cap used by SteamVR without the explicit maxRecommendedResolution setting. So the automatism actually made sense. But with manual supersampling controls working now, I at least know that aliasing can be reduced a lot with a new GPU (tried 300% SS - completely unplayable but it looks nice for sure!).
    Haven’t applied all suggestions from the link above yet (just maxRecommendedResolution), so manual settings might be able to achieve better results than the automatism while keeping frametimes in noncritical areas. Will try this out!

First conclusions:
Text on virtual monitors (like in Virtual Desktop or BigScreen) and games like Alyx look noticeably better on the 8kX than on the 5k+. Currently I’m glad that I kept the 5k+ though (mainly for sports games where refresh rate makes a difference for me and it’s less sweaty). But for most things the 8kX is definitely an upgrade. And if the 118 Hz mode works as well as the 120/144 Hz mode of the 5k+ at some point (which should hopefully be fixable via software updates) then there wouldn’t be much reason left to further use the 5k+. All in all, I’m happy with the device and glad that I pledged for the 8kX! Some tuning would still be helpful, but the 5k+ also went a long way when comparing the current experience to the initial one. So I’m optimistic and will keep the 8kX.

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Great review, thanks!

Did you edit the SteamVR max res settings via the ini file to allow for proper supersampling?

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Congrats on your 8kx and thx for taking your time for this review!

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yes, that’s the current setting inside steamvr.vrsettings (have taken out renderTargetMultiplier again to make sure it’s not overriding anything - it also didn’t change anything though, had that value between 1.0 and 4.0, no change either):

"steamvr" : {
      "maxRecommendedResolution": 16384,
      "background" : "#FF000000",
      "installID" : "9025419486360871781",
      "lastVersionNotice" : "1.10.32",
      "lastVersionNoticeDate" : "1584997241",
      "mirrorViewGeometry" : "455 321 1080 600"
   }
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Da fehlen die Krähenfüße

And congrats to your X!

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Thanks for the review! Glad to read that everyone so far has been overall happy with the X.

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Thank you for the review & impressions.
So as some people like yourself see the colours as same as the 5k+ & some other people see as same as the index, i think this is something I will need to see myself when I get mine.
I always saw the 5k colours as a bit too dull, but Index & og 8k as good enough.
Also it’s Interesting for me that it seems the comfort kit moves the sweet spot for some users.
As someone who’s eyes never really fell naturally into the 5k/og 8k sweet spot (meaning I used to adjust often), I’m hoping that maybe this comfort kit naturally lines my eyes up better.

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Thank you for taking the time to post your impressions. :0)

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Just as a remark: Don’t quote the number, it is either unnecessary or invalid (and might thus be deleted by SteamVR). Best follow this guide for reference: https://community.openmr.ai/t/how-to-make-your-pimax-image-crisp/29688

Old text:
Thank you, that was indeed part of the problem :blush:
Now the visual quality and frametime react a little. But less than I would have imagined. Can definitely see a difference between x0.5 and x5.0 now. But x0.5 doesn’t look as bad as I would have imagined and x5 not too much better than the previous default. And frametimes are (higher than at x0.5) but still quite low. So I wouldn’t be surprised if there is another cap involved.
Things would be so much clearer if these caps would actually be shown via the various sliders. Then one would see - ok, does seem to stop here, let’s find out why.

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Have you try to make a complete uninstall pitool/SteamVR incl. all Data in the Userdings ( c Benutzer App data) ?
And then make a clean install?
maybe old 5k data is still hidden there.

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Not yet, can try that tomorrow. As e.g. the Pimax guys are jumping back and forth between headsets I’m not sure whether this is the solution. But it’s worth a try.

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Eh, I hoped Pimax did something with contrast & colours, coz e.g. on 8k (OG) seems colours are better IMO considering through the lense videos.

hopefully BB pitool update can affect it

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Yeah it’s interesting how people seem to judge colors differently. Some said the colors are on par with the index, which would be great. But if it’s on par with the 5k+ I’d be disappointed.

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Can’t help you there, haven’t seen an Index in action yet :slight_smile:

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added notes regarding audio.

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By default I didn’t think it was great blacks, everything looked a bit washed out, but looked a good bit better with Sweviver’s recommended contrast and brightness settings

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Interesting, thanks for the feedback! Was initially checking whether I can get things a little brighter - which wasn’t a good idea, so I turned everything back to default (like on the 5k+), didn’t experiment too much with turning it into the other direction yet. Will play around with the values again to see whether things get better! “Like the 5k+” wasn’t meant as a negativism. Sure, the Vive has better colors, but the 5k+ is LCD, so… Perhaps I have set my expectations a little too low and more is possible? If yes - all the better!

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Um, actually, no it doesn’t. The original value wasn’t quoted, nor is my larger value, and it works properly for me.

The most important thing is to make sure you are editing the correct file (location can vary) and that you have no syntax errors (otherwise SteamVR will ignore your changes and rewrite the file). You need a comma at the end of the line, unless the line is at the end of the list and you need to use the standard (not “pretty”) double-quote character; this one: " .

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Ok, good to know, think I also copied it out of some tutorial without quotes.
It doesn’t rewrite my file in either case. Have used the one under C:\Program Files (x86)\Steam\config (if I remember correctly, not in front of my gaming PC atm.)
I thought it started to make a difference when I added the quotes - before I couldn’t see any changes, then x0.5 was slightly worse and frametimes slightly better.
Perhaps Steam Home isn’t the best test program and overwriting/ignoring some stuff? Will experiment more with other applications later today.

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You know it is working, if you have it to a high value and you bump SteamVR’s video quality setting to something like 300% and a game runs poorly (is a stuttery mess).

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