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Nvidia GeForce cards' 3D stereoscopic output over HDMI purposely gimped

n13L5

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Joined
Jul 12, 2012
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45
As far as my research on the net went, Nvidia is purposely gimping stereoscopic output to any HDMI monitor that the manufacturer didn't pay them a license for.

How so, you ask? Putting out a Stereoscopic 3D signal to ANY television or monitor over HDMI is limited to either 720p @ 60Hz or 1080p @ 24 Hz!

24 Hz you ask? why? Why did I pay extra for a "3D capable" Full-HD flatscreen tv with 120 Hz refresh??


Well, I didn't pay yet, I read stuff on the internet, then I went to the store several times and tried with different brands of televisions. If you have an Nvidia card, its always the same crap - it won't let you do what you want.

If you have an AMD card, you have to pay $20 or $30 extra to buy a piece of 3D stereoscopic software, but neither the Radeon card nor the software dares to limit your output options to something preposterous like 24 Hz.


Truth is, Nvidia's "3D Vision 2" produces the best output currently available for games, thanks to its LightBoost technology (which is also built into the M17xR4, if you bought the 3D bundle). But availability of Monitors with LightBoost is pathetic and limited to some 23" monitors and just two 27" monitors from Asus. Everything else listed on Nvidia's site as 'compatible' does NOT have LightBoost support and so, you don't get the main feature that makes it look good.

Without LightBoost, you might as well get anything, cause by comparison it will be dark and flickery. And while Panasonic televisions have very nice active 3D technology, your Nvidia Card won't send it a useable signal.


And from what I saw on the net, its because Nvidia is being particularly greedy. They will only send proper HDMI output if you buy their pro version Quattro cards with some authorized Mitsubishi television screens that also don't have LightBoost.


Without LightBoost and the new glasses, Nvidia's stuff is nothing special, no matter the advertising. If a 3D Alienware laptop with 17 or 18" screen, or a 27" Asus display (that does great at 3D but is an otherwise mediocre TN panel) is good enough for you, by all means, Nvidia will serve you well.

But if you want to use your TV or any other bigger HDMI screen, you can forget Ngreedia and are better off with AMD - or else - just wait another year, cause Windows 8 will have a Microsoft built 3D stereoscopic API for game companies to write to. Before long, Nvidia will be forced to support that, without any artificial limitations.



If you have further insights, corrections or questions, please let me know. The details on 3DS are not easy to come by.


I guess its sort of a rambling post for now, I might edit it later to give it better continuity ;-)
 
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VagrantXeth

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Mar 4, 2012
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321
I always thought that the reason for limitations on refresh rate were because of the processing load the GPU underwent with stereoscopic graphics (essentially because the card has to render two images at desired or capable resolution plus effects at once).
 

n13L5

Member
Joined
Jul 12, 2012
Messages
45
I always thought that the reason for limitations on refresh rate were because of the processing load the GPU underwent with stereoscopic graphics (essentially because the card has to render two images at desired or capable resolution plus effects at once).
1) GPU rendered frame rate is independent of vertical refresh.

your GPU could render only 15 fps and the graphics card will still refresh at 120 Hz



2) but with your HDMI output being artificially limited by Nvidia to 1080p @ 24 Hz means no more than 24 fps can be sent.

If your GPU renders a perfectly smooth 60 fps in a given game, a 24Hz HDMI output limitation makes 36 of those frames be a waste and your game still look like crap.



3) Even if my GPU was going to drop below 30 or 60 or whatever number of frames per second, the graphics card still refreshes the screen at the set frequency, it just happens to be the old frame still in the buffer, if a new one wasn't rendered yet. This is how its possible that your frame rate can fluctuate all the way down to 3 fps, yet your screen doesn't start to flicker.

Nvidia's 3D Vision 2 mandates displays with 120 Hz vertical refresh. This is, so the shutter glasses work fast enough to keep the flicker from being too annoying (its always noticeable).

AMD's cards will put out a 1080p signal at 60 Hz or at 120 Hz through either DVI or HDMI with no artificial limitation.
 

n13L5

Member
Joined
Jul 12, 2012
Messages
45
HDMI LLC. decided in January 2012 to crack down on Manufacturers who list version numbers on the box or on the cable: can't specify 1.3, 1.4, 1.4a or 1.4b anymore...

This will make it even harder to pick the 'right' cable... anything before 1.4a doesn't support 3D signals at all...
 
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