Oculus & Nvidia G-Sync

Carmack has answered this: https://twitter.com/id_aa_carmack/status/391299110344867841, quote: "G-Sync won't work on any of the display panels Oculus is considering right now, but it will probably be influencing many future panels."

G-Sync will not work with any panel, ideally you want a 120Hz panel to get the lowest possible latency: The frame redraw takes only 8ms instead of 16ms. You also have a minimal refresh-rate with G-Sync: You can't drive the display a 1 FPS, instead the lower limit might be 40. This means when you are running between the minimal and maximal frame-rate you won't have tearing and a latency of the screen update rate (8 vs 16 ms). If you drop below, the screen has to refresh and will refresh the last frame. If you are just below that limit (e.g. 39 FPS) that means you have to wait one refresh before you can display that frame, again, 8 < 16. Of course you could introduce tearing (only) in that case (similar to the swap_control_tear OpenGL extension).

So, we want a 120Hz display with G-Sync, but also more than FullHD, right? 2560*1440 pixel smartphone screens are available... Sadly, I'm not aware of a display connector with the required bandwidth for both (10.6 GBit/s) that is already widely available (HDMI 2 could be an option in the near future).

Will we see 1440p or 4K G-Sync 120Hz HMDs? Sure, but most likely not in 2014...

"renderingpipeline" wrote:
Carmack has answered this: https://twitter.com/id_aa_carmack/status/391299110344867841, quote: "G-Sync won't work on any of the display panels Oculus is considering right now, but it will probably be influencing many future panels."

It's interesting.. Carmack was actually one of three speakers at the NVIDIA press release event for gsync. That leads me to believe that there may be an openness to it being a core component of the release OVR product. Sure, he said it wouldn't work on any of the display panels they were considering right then.. but that debate is probably still fluid and ongoing and to say anymore would be premature.

It's a more complicated situation as it becomes a deeper and exclusive situation with NVIDIA.. but both sides may have something to gain and it could be the subject of negotiations. It could be that NVIDIA takes some ownership over delivering the panels? who knows.

If you're going to put latency first, then you'd have to consider g-sync as a possible superior option at somewhat of an 'exclusive' cost.

As an arm-chair theorist I'm thinking the release will be powered by g-sync tech.. and more importantly, I think we'll find there's a much deeper relationship between Oculus and Valve then we've been led to believe.. People at OVR seem to be far too giddy at just the mention of Valve.. when they should allegedly be OVR's number one competitor in the VR space with their own product announcement in February.

very excited for the season finale!!

From one of the latest interviews to Brendan Iribe, I was under the impression that the latest prototype rift sported an OLED screen, and the same would probably happen with the consumer version.
He also stated the actual total latency is in the 10/20ms range, which is impossible to achieve with a 60hz LCD screen.
So, if they use an OLED that can have a very high framerate well beyond 120hz, there's no need for the g-sync technology, since the tearing will not be visible anymore even with vsync off.

I dont understand why the refresh is made from top to bottom.
When we know that most of movment in FPS are made from left to right or right to left, tearing would have less impact if the refresh was made from left to right.

"Tgaud" wrote:
I dont understand why the refresh is made from top to bottom.
When we know that most of movment in FPS are made from left to right or right to left, tearing would have less impact if the refresh was made from left to right.

On the contrary, tearing would be far more distracting. You'd get vertical tearing lines, and the game world would be in two different positions on either side of the tear line. At least with current tearing the tear line doesn't obscure anything, but with vertical tear lines it would look like the world was two sheets of paper with a variable amount of overlap...

Well, from left to right, the tearign would only concern one vertical line of pixel.
like a little "compression", its not that disturbing.
moreover we have far more vertical line than horizontal ones, on modern screen.
So this "compression line" will be far less visible.


when we have top to bottom refresh, we have half of the screen not coherent with the bottom.
and we have all vertical line who are "false" and splitted in two.

but its only my opinion

"crespo80" wrote:
From one of the latest interviews to Brendan Iribe, I was under the impression that the latest prototype rift sported an OLED screen, and the same would probably happen with the consumer version.
He also stated the actual total latency is in the 10/20ms range, which is impossible to achieve with a 60hz LCD screen.
So, if they use an OLED that can have a very high framerate well beyond 120hz, there's no need for the g-sync technology, since the tearing will not be visible anymore even with vsync off.

I heard that one.. Something also about how OLED frames are on for extremely short bursts as opposed to much longer LCD frame holds.. Easier on the eyes/vestibular.

Maybe its an OLED-GSync solution? ... That would be sick.

I'm perplexed by all the latency numbers going around.. on the DK1 I can already get down to 17ms..(according to the latency tester) .. and I know they've made improvements. If they can somehow get to 5ms, it's gonna be over.

That would be a real game changer.

"antigravity" wrote:

"renderingpipeline" wrote:
As an arm-chair theorist I'm thinking the release will be powered by g-sync tech.. and more importantly, I think we'll find there's a much deeper relationship between Oculus and Valve then we've been led to believe.. People at OVR seem to be far too giddy at just the mention of Valve.. when they should allegedly be OVR's number one competitor in the VR space with their own product announcement in February.

I think we'll definitely hear an announcement that ties Oculus and Valve together. My current theory is that Oculus has been focusing on the headset (Rift) while Valve has been working on an affordable VR machine (Steam Box), VR controller (VR Steam Controller), and of course software as well. It may not be ALL of those things, but Valve has to have some skin in the game somewhere.

As for G-Sync, it would only be advantageous to the 5% of gamers who can afford to get their hands on a G-Sync compatible video card next year, so I doubt Oculus would hinge the success of their hardware on that kind of technology. For v2 or v3, though...

Oculus has stated that it has a few more tricks up its sleeve that we haven't heard about yet, and everyone seems very excited about what's going on behind closed doors, so it'll be veeery interesting to see what they've actually been up to these last few months!

"Tbone" wrote:
I think we'll definitely hear an announcement that ties Oculus and Valve together. My current theory is that Oculus has been focusing on the headset (Rift) while Valve has been working on an affordable VR machine (Steam Box), VR controller (VR Steam Controller), and of course software as well. It may not be ALL of those things, but Valve has to have some skin in the game somewhere.

Yep, That sounds about right.
From a distance it seems like it could fit together well.

"Tbone" wrote:
As for G-Sync, it would only be advantageous to the 5% of gamers who can afford to get their hands on a G-Sync compatible video card next year, so I doubt Oculus would hinge the success of their hardware on that kind of technology. For v2 or v3, though...

My understanding of it, and I could be wrong, was that most nvidia cards would be automatically "g-sync enabled" from drivers.. So allegedly a gtx-480 from a few years ago could power a g-sync device.

In that case the market share would be much larger, but of course still cutting amd users out.
who knows ??

"Tbone" wrote:
Oculus has stated that it has a few more tricks up its sleeve that we haven't heard about yet, and everyone seems very excited about what's going on behind closed doors, so it'll be veeery interesting to see what they've actually been up to these last few months!

Couldn't agree more.. this could go in so many directions.

G-Sync sounds like a cool piece of tech. But the fact that it's vendor-specific really irks me.