Version 3 prototype review

Ok, here’s my more detailed review/first impressions of the V3 prototype of the pimax 8k. I own an oculus rift so I will primarily be comparing to that but I have demoed a few vives as well so I know what they look like and their capabilities. I tested the V2 earlier in the day for the first time as well, so I will compare to that also.

Comfort: They didn’t have the upgraded head strap with built-in headphones for either the v2 or v3 demo yet (they said they only have a prototype in China right now), but even without that the comfort was very good. The headset is very light, lighter than the oculus rift, vive, or gearvr and it felt good on my face and seemed to stay in place as I moved my head around quickly. The one negative that I noticed with the v3 is that the lenses were extremely close to my eyes; my eyelashes were touching them and created a bit of discomfort.

FOV: Certainly better than the rift or vive and it was nice to have my vision opened up compared to those. It didn’t quite wow me the way I thought it would; I didn’t do any scientific tests, but I wouldn’t have thought it was a full 200 degrees. Pimax said they are only using about 80% of the screen right now and they will be tweaking the lenses more with v4 and v5 to try to get that utilization to 100% so maybe the fov will increase a bit also.

Resolution: This was markedly improved over the ridt/vive, especially for text. Distant objects were more visible and clearer. However, some of the games didn’t have supersampling on and you could definitely see jaggies. Because the pixels per field of view are not exponentially higher than the rift/vive due to the input resolution being 5120x1400 upscaled to the full 7680x2160, the increase was not as much as you’d think given the rift is 2k and this is 4Kx2. I’d like to see some supersampling added to see how this improves but the desktop 1080 the demo was running on was struggling to even maintain 75fps so you’d need at least a 1080ti to even consider that.

SDE: Screen door effect was the one area in my opinion exponentially improved, especially over the vive. I had just demoed using a vive before trying the pimax and the difference was night and day. It is visible if you look for it but it’s easy to get immersed in the experience and not notice at all, unlike the rift/vive where you’re constantly aware of it in the back of your mind at least.

Display and lens quality: This is where things get the most uncertain. After noticing that things didn’t seem very smooth, especially when physically moving my body around, I asked the CEO what refresh rate it was and at first he said 90hz, but when we pushed him and asked if this demo here was actually running at 90 he then said no, both the v2 and v3 were actually running at 75hz. When we expressed disappointment and reminded him that the kickstarter prominently advertises 90 and that no where they had said the prototypes weren’t running at the full 90 he apologized and said they were working hard to try to get it operational. He said something about supply chain issues, that the display processing board said in the specs that it could do 4k at 90hz but they were having issues running it at more than 75 at the 5120x1400 input resolution. It seems like they are quoting 90 when asked in faith that they will work out the issue. Hopefully they do, but it’s a risk to consider as the kickstarter nears funding. So far I haven’t compared the v2 to v3 much and that’s because the only real differences are the lenses used and the cable being a single displayport cable instead of two hdmi cables. When I tested the V2 earlier in the day I noticed some distracting distortion on the edges of my fov that made moving around a bit disorienting. Thankfully, the V3 largely solved this, but there was still a small bit on the edges. I tested this by looking at the circle steamvr makes on the floor when in standing only mode and the circle got a bit elongated if viewed in the periphery. Also, the way the V3 lenses work, there are three parts to each one, an inner lens similar to the V2, and what looked like two outer lenses pasted together for the outer lens. It was at the seam where if I viewed a static object straight on then moved my head so I was viewing out of the periphery, the object would jump slightly to a different location when it passed the seam. This is something pimax said would be corrected in the next prototype version, since they said all the pieces of the lens would be integrated into a single lens. Finally, the display itself: I didn’t notice any ghosting, even when moving my head around quickly. The black levels were also very good for an lcd, not as good as the rift /vive but the God rays were much improved so I’d rather have the slightly worse black levels. The colors and brightness are the one area I’d want improvement. I asked if the brightness could be adjusted and they said it could, they called one of the engineers in China to increase it for me in the software but after talking for a few minutes they determined it was too difficult to do in the limited time we have so unfortunately I couldn’t test at any other brightness than the default.

Tracking: Tracking seemed very good, as accurate as the rift/vive when moving my head around, the only issue I saw was when positionally moving, it was not as smooth. I don’t know if this was due to the lower 75hz refresh rate or with the tracking processing but it uses the valve lighthouse system so it shouldn’t be a permanent issue as long as the refresh rate problems get sorted.

Individual game impressions: There might be a bit of repetition in this section but I’ll let you know what my thoughts were with each title.

theBlu- This is the only experience I tried with the v2, colors and contrast seemed good, close to what I remembered on rift. The underwater world was much clearer and more immersive due to the fov and lack of sde.
Elite Dangerous- We started in the menu screen ship bay and then tried getting in the cockpit, but couldn’t really do much else other than physically moving around since they didn’t have a controller. Text was much more readable in this vs rift/vive and distant objects clearer. There were still some jaggies so I went into the steam settings to try to enable supersampling but the team member stopped me, saying supersampling wasn’t working yet.
Project Cars 2- Again, I couldn’t do much other than move around physically and I was able to go forward by pressing the up key on the keyboard but turning wasn’t mapped so didn’t get very far. Like elite, the cockpit text was noticeably better and looking through the windshield at distant objects was a lot better also, but still not perfect.
Onward - This one started glitching and had an out of memory error after a couple minutes but I did notice the improved distance views and clarity but also noticed the lack of brightness the most in this since it was supposed to be a bright desert daytime scene but it looked a bit washed out and dim. Again, they claimed the brightness will be adjustable but I wasn’t able to test it.
Eleven table tennis - The lead developer was at the demo with me and he was testing a build out to see if he would have to change anything to support the pimax. It looked good and clear; there were a couple issues but he said that was because he was running a build that wasn’t through steam because pimax didn’t have it preloaded on their computer so he had to load a light build off a usb drive.

Let me know if you have any specific questions about anything I missed, and apologies if there’s any grammatical errors or typos, I wrote this on my phone waiting for the plane to take off. Overall, I’m still keeping my kickstarter pledge because of the benefits of the higher resolution, sde, and fov, but there are definitely some concerns that need to be addressed. I have doubts that everything will be solved by January when they’re planning to ship the units but they seem to be working hard and are knowledgeable about the issues. They are also very eager to listen to feedback and monitor the forums to see what people’s priorities are so make sure you vocalize your top concerns so they’ll prioritize solving those first.

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I wont lie, the 75hz stuff is a bit of a butt clencher if the problem goes all the way back to the chipset.

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Thanks evertec!

The issues you mentioned are concerning, hard to know if these can be fixed.

However, some of the games did not have supersampling on and you could definitely see jaggies. Because the pixels per field of view are not exponentially higher than the rift / vive

Like the elite, the cockpit text was noticeably better and looking through the windshield at distant objects was also a lot better, but still not perfect.

Would you buy 8kx?

Isn’t having only one cable going to be a limiting factor regarding supersampling?
Will the upscale chipset be able to deal with different input resolutions when using supersampling?

Is Pimax considering a second DP cable for the final version, even if we don’t use it until Volta is here.

90Hz has been a huge selling point. They have been some what just telling people it’s 90Hz when it isn’t actually yet. I hope they can give some reassurance here that they will meet that goal.

First, thank you for the review - it sounds much more believable than other fan-posts. They try to solve many problems at once and this rises the risks for cross effects. I really hope this will be a successful device!
My question according to your experiences especially according to Elite Dangerous:
Would you personally buy this device if you already have a Vive or CV1?
I know there are a lot of improvements from a technical point of view, but I just want your personal subjective opinion - did it look really much better or just a bit?

lying about the 90hz doesnt fill me with confidence. I’m not sure if its a deal breaker or not. i still have time to cancel my 8k headset

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It sounds like they are making good progress. 75hz doesn’t scare me that much because literately hundreds of people play Gear VR (60hz low persistence,) and don’t have issues. 90hz is mostly for those who get sim sickness. Pimax has to fix it, but its not the end of the world.

That said, @anon23564932 you should really tell the team that not being up front about this 75hz issue, and not being up front at the beginning (before Kick starter began,) about the native input resolution being 1440p per eye upscaling to 4k was not a smart decision.

Yesterday, in bigscreen, I had to explain to several people that this headset would run on a 1070, in spite of their disbelief. They wouldn’t believe me because they said, “How can you run 4k per eye with today’s hardware? Its not possible” whereupon I had to explain to them the actual specs of your device, IE “Its native 5k panoramic upscaled to 8k panoramic.”

Unfortunately, you guys are having a situation where your marketing 8k is actually getting you in trouble. This is because its inadvertently not clear to people what the device actually needs to run. If you would like, I can try and help make some suggestions to improve the ads?

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Thank you @evertec for finally technical review. It has answered some of the questions I have indirectly and later directly asked to Pimax and which they avoided to answer.

  • which supersampling was used in demos ==> none
  • what was the refresh rate used in the demos ==> 75 Hz

This finally makes sense since I was pulling my hair over the simple math I did which told me that what Pimax claimed could not work.

Coming to your review:

  • Do you know at which resolution the demos was rendered? I guess if they do not use the full display size they could render smaller sizes. I am talking the scene rendering before pre warp transformation.

  • Do you know which subpixel arrangement use the displays in 8K?

  • Has Pimax indicated if the problem with 90 Hz refresh was related to panel logic or to the upscaler?

Just one note to supersampling. No supersampling should manifest as aliasing progressive from the centre of view to the edges as the geometry loses precision due to lens warp. Did you observe something like that?

I would not call that a lie, it’s a feature not yet implemented, we are talking about a prototype, who said that the headset was ready?

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@evertec Can you tell more about FOV in Elite ? Especially cokpit HUD ? Do you had WOW effect ? :slight_smile:

Totally agree. This isn’t the first time they have lied or misled backers. I had already reduced my pledge from a full 8K kit down to just the headset and unless they can offer reassurance that the 90hz is going to be met. I may just pull out and buy a Samsung Odyssey instead.

I play a lot of Sims, so the refresh rate is important to me the Odyssey seems to have a better display than my current Rift and it was only the FOV that was pushing me towards the 8K. All those stretch goals mean nothing if they cant get a decent headset out.

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They have been telling people at all the demos it was 90 hz, some reviewers already said they found that hard to believe. And initially the ceo claimed here again it was 90 hz. I had hoped pimax would have learned from the 4k be debacle that lying is not a good strategy, the community will always find out

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Thanks for the detailed impressions! The 75hz issue is a big deal and I am sure they are working hard to resolve it, but my concern is that it will simply not be possible to fix it due to the actual limitations of the chip, regardless of what the chip’s spec sheet says. I will probably still keep my pledge for the headset only because the other benefits still sound great and one thing I love to do is watch 3d movies and this should make that much more enjoyable even at 75 hz. I do really hope they can resolve that issue though. I also wonder if the brute force of a Volta card would be able to push the framerates up next year. I currently have a 1080ti but would have no problem selling it and upgrading if there is a big jump in gpu power.

Do you know which subpixel arrangement use the displays in 8K?

They claim its RGB stripe, but a review done yesterday had pictures posted which to me suggest a pentile arrangement.

“I would not call that a lie, it’s a feature not yet implemented, we are talking about a prototype, who said that the headset was ready?”

What would you call it then? They said it would run at 90hz, they even state that on their kick starter page. They avoided answering the question until pushed and then finally come clean that its only achieving 75hz. Its been mentioned, they did the same with native resolution.

They dont come across as an honest bunch and if they had been up front about it from the beginning and said it was a problem, but they would guarantee to fix it before shipping. I would have more respect for them.

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im honestly wondering if the chipset issue will force them to make the default an 8K X like 2 chip arrangement.

They say on KS than v3 would be running at 90?

Can you explain more what game get refresh rate at 75 Hz, it happen with all game or only some high spec game?