8K X Initial Review - Primarily compared to HP Reverb and Valve Index

I just received my 8K X yesterday and after initial trouble getting it connected (I ended up having to plug the 2.0 USB plug into a 2.0 port, not a 3.0 port), then having issues getting it to track (I had to wipe SteamVR and reinstall), I finally got up and running. For reference, I’m running on an i7 8700K with a 2080ti GPU, 32GB RAM.

FOV
This is the big selling point of the Pimax headsets and the 8K X certainly delivers. I did some A/B comparisons with my HP Reverb and even on Potato mode the 8K X has a bigger FOV than the Reverb The options on the Pimaxes are Potato (100 degree FOV), Small (120 degree FOV), Normal (140 degree FOV), and Large (160 degree FOV). Despite the huge difference in FOV between even the previous Pimaxes and any other mass market headset, I still preferred the Reverb prior to the 8K X even though it has about a 95 degree horizontal FOV because of its high pixels per degree, but it really is jarring to go back to the small FOV especially after just using the 8K X; the Reverb looks like binoculars or swimming goggles until you get used to the small FOV again and even then it doesn’t provide nearly the same level of immersion in this category. The Index is a bit higher FOV than the Reverb, but even the Small FOV on Pimax is still wider.

Screen Quality
The screen is very good quality and completely blows away the Index in terms of pixels per degree and SDE, and matches it in colors and black levels. I used Sweviver’s recommended contrast setting of +2 and brightness setting of -2 and that really made the black levels quite good for an LCD headset. The brightness of the panels at those settings aren’t as high as the setting I was using on the Index, but it’s certainly acceptable on all the titles I tried. Compared to the Reverb, it isn’t quite as sharp, even when I cranked up the supersampling so the pixels per degree are likely a bit lower. However, the fill rate seems a tad higher so the pixels are very hard to detect, and gives a nice solid feel to objects. The Reverb had a good bit of a perceivable mura effect, and the 8K X also has this to a certain level, though not as bad as the Reverb, and it’s really only visible on very bright areas.

Lens Quality
This is where the 8K X falls down a bit. The wide FOV Pimax headsets have always had a bit of distortion, primarily on the edges of the lenses, but also some warping in the middle. The middle distortion has been largely fixed on the 8K X, it looks similar to the Index in the middle now, and better than the Reverb (The Reverb has some barrel distortion). The edges are still blurrier than either for me, and have a bit of distortion as well, but it’s not significantly worse than the Index for me. I know some people have said they have edge to edge clarity on the Index, but I could never get that and it actually has worse edge to edge clarity than the Reverb. The bigger issue for me is I can’t get the lenses adjusted quite narrow enough for my low ipd (~58mm) so I have more eye strain than any of the other headsets I’ve used. It’s not terrible during the short sessions I’ve used it for, but it remains to be seen how it does with longer sessions. God rays/internal reflections are very minimal, much less than the Index and similar to the Reverb.

Audio
As others have said, the SMAS audio is not good. I really don’t know why they’re making the default audio for a $1300 headset Rift S/Quest level audio (Both of which I couldn’t stand so I added headphones or a DAS to them). It’s serviceable to a minimum level, and is loud enough to hear, but it just doesn’t immerse with bass like the Index or even Reverb audio do. Hopefully the DMAS comes soon and brings it up to Index level or beyond.

Comfort
Compared to the old Pimax 5K+/8K straps the comfort kit is much better. Mine came with the thin foam preinstalled, but no other foam options. Compared to the Reverb it is a good bit less comfortable, it is much heavier and front heavy and needs to be ratcheted tightly to keep from sliding around and to keep it in the sweet spot. Compared to the Index, it is still less comfortable but it is more similar in weight. The face foam also doesn’t quite fit my face right, it needs more foam or to be curved more to fit my face better, I may try bending the plastic or adding some foam to the left and right edges to get a better fit. I like the concept of the open speakers like the Index, since they are more comfortable, so hopefully the DMAS is better quality while still being off ear.

Software
This is another area that needs improvement, and according to Pimax will soon be greatly improved with the introduction of their VR launcher/cloud profile/settings app. As it stands, it’s difficult to know which apps work best with which settings. Things like Parallel Projections are required for some apps, but not others, but it is too much hassle to figure out which ones work and which don’t so I just leave the setting on all the time, which sacrifices performance in the apps that don’t need it. I do like the level of customization available, with settings to change the render resolution, field of view, motion smoothing, IPD offset, upscale mode (118 hz), and fixed foveated (dynamic foveated supposedly coming in the next couple weeks), and 6dof/3dof tracking options, but it would be much better to have the profiles automatic for each game and an interface in VR to launch those profiles (which is also supposedly coming in a few weeks). The 8K X definitely needs as much GPU as you can throw at it, even with my 2080ti I have to run most games at less than 100% Steam supersampling to get a stable 75 fps to match the refresh rate of the native mode. I’ve settled on keeping the pitool set at 1.25 resolution, and just bringing the Steamvr resolution down to where it’s stable, and most games need to go down to 50% or less. Hopefully the Dynamic Foveated Rendering with eye tracking will fix some of the performance issues.

Conclusion
I have or have had just about every consumer VR headset made to date, and I can say that overall, the 8K X is the best one yet. It’s not perfect, and has flaws like any other headset, but the benefits outweigh the minor issues. Playing Half LIfe Alyx in the 8K X brings the already high immersion with headsets like the Index and Reverb even higher and really makes me feel like I’m in real life at points. I also have the Reverb G2 on preorder, and it will likely be a better value for most people at a third of the price, but I feel like it will be hard to top the 8K X for enthusiasts who want the absolute best immersion in a VR headset.

Edit: The longer I use this, the more I think it’s not going to work for me because of my low IPD. As I play games for longer periods the eye strain is just so bad, and coming out I feel crosseyed and have a headache for a while. I found a user who modded his 5K XR (https://www.reddit.com/r/Pimax/comments/ewab3l/extreme_ipd_mod_done_no_more_eyestrain/) but I’m not sure the X would be exactly the same process and I’m not comfortable doing so much modification on such an expensive device. @PimaxQuorra @PimaxUSA @SweViver Do any of you have any ideas on how to make this work for me? I’ve already tried many different software offset values but the physical lens sweet spot is just too far apart for my low IPD. I really want to use this since it’s superior in so many other ways to my other headsets but I may have to sell it if I can’t figure out a solution.

73 Likes

Great detailed write up.

Thanks for taking the time for sharing your thoughts.

4 Likes

Thanks for this comprehensive review. Did you try the software IPD adjustment for your 58 mm IPD?

1 Like

Yes I did, but still have the feeling of eye strain. Everything looks fine though, just makes my eyes feel like they’re doing more work to see correctly.

2 Likes

Have you try the additional digital IPD Setting for you really low IPD?
For me, in the 8k+, I must go 4mm lower then my real IPD.

Edit - Ahh, to slow…

I’ll try even lower, I did -2 but I’ll try -4 or -6 if you’re saying they don’t match with real IPD numbers

Wonderful write-up @evertec, thanks this is helpful

3 Likes

Regarding not as sharp as reverb, just wondering did you apply the steamvr config tweaks as sweviver provided or this is with the tweak already?

2 Likes

Thanks for your nice review!
Interesting Point that the X is not so sharp as the reverb.
I have a 8k Plus and in No man`s sky it is as sharp as with the reverb (I had a reverb for a few days for testing at home).
So the X should be better than the Plus in every case.
But i think it depens very on the game, which you are playing.
Maybe the upscaler is just perfect for NMS.

But In ED there is a big difference in sharpness between the Plus and the reverb.
ED is maybe not made for an upscaler.

I will see as soon as i get the X, if the X is gonna be as sharp as the reverb (for me personally).

2 Likes

He did, but it doesn’t matter since he says he’s undersampling instead of oversampling. It only matters if you want to go beyond the default 4k render size.

2 Likes

What are the refresh rates for different FOVs? Is there 60Hz?

Yes this is with the 16384 maxrecommended resolution. I tried even with everything at 100% resolution and it still wasn’t quite as sharp as the reverb, but it’s not far off.

3 Likes

Nope, the only refresh rate for any FOV is 75 with native mode and 118 with upscale mode.

2 Likes

I think it probably depends on the antialiasing the game uses. With No Man’s Sky, it uses very blurry antialiasing so you won’t notice the difference as much with a high res headset. With games like HL Alyx, Boneworks, and others that use MSAA, you get a much sharper image so you would see the differences more. A lot of games I just turn off the antialiasing completely if it’s a blurry method like TAA or FXAA.

5 Likes

That’s because they went bold and put it at that price point because we forum enthusiasts told them it would be worth it if the hmd performed as intended.

Not sure what your trying to say? Don’t you feel at $1300 for the headset it should come with an audio solution that outperforms all other headsets? Not one that may or no be comparable to a $400 headset.

10 Likes

Cant wait, I will have to eventually break it to my wife that “yes honey, the man cave has moved, and it’s going to be the biggest room in the house”

:rofl: :rofl:

7 Likes

How is the X not as sharp as the Reverb?
Reverb isn’t even 4K per eye.

If you mean pixel density then a 90 FOV (claimed 114) headset should not be compared to a 160-165 (claimed 170) headset.

Otherwise we can make a Reverb G2.5 and with 30 FOV and claim it’s sharper than a Reverb G2.

1 Like

Thanks for the review.
It sounds realistic & unbiased.
If the colours, blacks & brightness are as good as index, then it should be good enough.
That was my biggest worry.
To me I wouldn’t want to downgrade the colours to anything less than that as already index colours are barely enough for me.

However I am someone who gets perfect clarity & no eyestrain from index so I wonder if I’ll like going back to the pimax same lens design.
But if the comfort & res are a good enough bump up, then I think I can accept that.

Shame about the audio.
One of the most expensive headsets, given some budget entry level audio as standard is a crazy decision I don’t understand

4 Likes

Thanks for the nice detailed impressions! Interesting note about the sharpness compared to the reverb. Would you say that the difference in sharpness is minimal or is it very obvious? This is definitely coming from the FOV difference between the headsets. Since you still gave the 8kx the best overall ranking i assume that the sharpness difference is not great enough for you to prefer using the reverb over it?