Pimax 8k kickstarter

Pimax said the fps problem is caused by one of the chips in the video path not performing up to specification. Pimax said they're working with their supplier to fix the problem. Unfortunately, I don't remember where I heard it. Reddit? Youtube? Dunno.
 
Creig said:
You also need to look at the version of displayport. I am no expert in the following, so please feel free to correct me if I make a mistake.

Pimax has stated that the 8K will use Displayport 1.4 which has a maximum throughput of 32.4 Gbps. The 8K HMD is receiving two streams of 2560 x 1440, one for each screen. Those streams are then upscaled within the HMD to the native 4k resolution of those screens. A single 2560 x 1440 data stream at 8 bpp (I am assuming here) at 90 Hz produces a total signal bandwidth of 9.95 Gbps. Two streams at those settings will add up to 19.9 Gbps which is well short of the maximum available bandwidth of 32.4 Gbps. The 8K X version which sends a native 4K 3840 x 2160 signal would require 22.39 Gbps PER SCREEN at 90 Hz for a total bandwidth of 44.78 Gbps. Which is probably why Pimax has said that the 8K X would require two DP 1.4 cables and one hell of a powerful video card. So by the best of my limited math skills, a single DP 1.4 connection should be more than sufficient for the requirements of the Pimax 8K at 90 Hz. So it appears ato me that DisplayPort is not the bottleneck here. Possibly the chipset they're using to scale the dual streams to 4K?

One interesting thing I ran across while researching this is that DP 1.4 also has two other features: One being Display Stream Compression which is capable of "visually lossless" video compression up to a ratio of 3:1 which could expand the available bandwidth from 32.4 Gbps up to 97.2 Gbps. This would allow the 8K X to utilitize a single DP 1.4 cable just like the vanilla 8K model. DP 1.4 also introduces Forward Error Correction which overlays the DSC transport and addresses the transport error resiliency needed for compressed video transport to external displays. Needless to say, it looks as if this could be of use to VR HMD manufacturers.
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Remember all of those speeds are only rated to 3 meters, or about ~10 feet. 10 feet from the output of your video card to the back of the headset does not leave much room for standing up and moving around. So with the longer cables those speeds drop. DP is packet based and it will start dropping packets.
 
BecauseScience said:
Pimax said the fps problem is caused by one of the chips in the video path not performing up to specification. Pimax said they're working with their supplier to fix the problem. Unfortunately, I don't remember where I heard it. Reddit? Youtube? Dunno.
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The chip is the ANX7530. Source

Vega said:
Remember all of those speeds are only rated to 3 meters, or about ~10 feet. 10 feet from the output of your video card to the back of the headset does not leave much room for standing up and moving around. So with the longer cables those speeds drop. DP is packet based and it will start dropping packets.
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The kickstarter page lists a 10 meter cable option for the 8k set. Must be fiber.

It'll probably cost as much as the headset.
 
Creig said:
They are listing the 10m cable at $60 plus + $10 for shipping. I'm guessing regular DP?
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10 meter would have to be fiber. No way Pimax can pull that off with regular copper. Google around for fiber displayport cables. They're so expensive most sites do the "call for pricing" thing.

This place lists prices. Click the "cable length" tab. The 10m cable is $750!

High frequency wireless (like TPCast) is obviously the way to go vs super long DP cables.
 
I don't think Pimax knows about DP cable transmissions. You can't just make cables how ever long you want lol. IMO it is the reason they are having refresh rate issues.
 
Vega said:
I don't think Pimax knows about DP cable transmissions. You can't just make cables how ever long you want lol. IMO it is the reason they are having refresh rate issues.
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I get the same impression. Someone mentioned the use of a RedMere like technology for the 10m cable but I'm highly skeptical.

It's a shame Pimax did all of these crazy add-ons. I think they'll get bogged down delivering them. Most addons are done by partners but integration takes engineering time too.
 
They are selling 10 meter DP cables and say they haven't even tested if it will work. wtf?

If they are having this many problems using a 5 meter cable, it's going to be funny when they test the 10 meter.

You cannot send a high bandwidth DP signal more than 3 meters on a "regular" cable reliably. That's why the spec is 3 meters. One reason why I am backing the 8K X is that it will use two DP cables, so should allow more bandwidth flexibility.
 


cool update... only thing I noticed was the wobbly base station, yet he said there were no tracking issues... perhaps the excitement of everything going on distracted him... still, exciting to see hands-on reviews...
 
Youn said:


cool update... only thing I noticed was the wobbly base station, yet he said there were no tracking issues... perhaps the excitement of everything going on distracted him... still, exciting to see hands-on reviews...
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I did not see any video of how it looks compared to Rift/Vive? Maybe we need [H] to give us a review!?
 
Very interesting, maybe HTC should buy out Pimax. Disappointing on colors like the Vive but still a prototype and hopefully that will improve. The wide FOV may indeed give that holodeck feel vice the tunnel vision approach of the first generation headsets. Screen door effect goes along with the wider FOV, images is more stretched out so that will continue to be an issue. Hope these come out sooner vice later in the end.
 
Has the warping around the edge issue with some people (most recently Linus Tips) been addressed in any way? Do the new lenses take care of it, or is it a software issue, or perhaps these guys who notice it didn't set something up correctly?

No doubt the extra FOV and resolution are huge pluses, it'd just be a shame if people are getting sick or annoyed from the experience after 15 minutes...
 
The picture quality does look better. When it has been out for a while and actually works and is supported, etc, then I would take it seriously.
 
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Also, who knows how fast Oculus or HTC will follow suit... no doubt they have similar headsets already in development and they have less incentive to showcase early prototypes
 
BecauseScience said:
It's a shame Pimax did all of these crazy add-ons. I think they'll get bogged down delivering them. Most addons are done by partners but integration takes engineering time too.
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If you actually look at the stretch goals/add-ons, most of them aren't all that difficult or are already working:

Extra face cushion - meh.
Deluxe headstrap with headphones - easy.
Customized prescription glasses frame - easy.
Headstrap cooling fan - easy.
Wireless transmission - This will probably be tricky. But I don't think they plan on working on it for awhile yet.
Eye tracking - Again tricky, but I doubt they'll be devoting many resources to it until the HMDs/Lighthouses/Controllers are finished and selling.
LEAP Hand Motion module - Already completed, I believe.
Scent module - WTF...
 
I can't wait to get my first VR PUBG chicken dinner win and get the scent!
 
Put some Liquid Ass in the scenter and one would be able to duplicate the Blazing Saddles bean scene. :yuck:
 
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