Basic question about FPS vs Hz in 3D
In my year+ having a 3D vision ready set-up, i think i've got a pretty good idea about how everything works. But there is still something that pops up on this forum a bunch that confuses me. Especially while I'm researching a potential projector purchase. I read all the time people discuss that 3DTV Play only supports 1080p@24Hz or 720p@60Hz. But i want to clarify what this really means. I had always come to think that the use of Hz would refer to the monitor/projector refresh rate while Frames Per Second (FPS) refers to the game rendering. So when people say 720p@60Hz, does this mean that the projector is displaying 60Hz meaning the game is only rendering 30 FPS per eye? Or are they refering actually to the game rendering 60 FPS per eye meaning the projector is displaying 120Hz? Likewise, if its only 1080p@24Hz, is that 12 FPS per eye or is that actually 24 FPS per eye and the projector is displaying 48Hz? The reason I ask is when gaming on my monitor in 2D, Afterburner is telling my that I get (for example) 60 FPS, but in 3D it is 30. But I assume that in 3D afterburner is really showing me FPS per eye. So assuming in a projector set up, the refresh rate is the limiting factor (meaning the graphics card will always render beyond the max refresh rate), shouldnt FPS always be half of the refresh rate of the projector? Thanks for setting me straight.
In my year+ having a 3D vision ready set-up, i think i've got a pretty good idea about how everything works. But there is still something that pops up on this forum a bunch that confuses me. Especially while I'm researching a potential projector purchase.

I read all the time people discuss that 3DTV Play only supports 1080p@24Hz or 720p@60Hz. But i want to clarify what this really means. I had always come to think that the use of Hz would refer to the monitor/projector refresh rate while Frames Per Second (FPS) refers to the game rendering.

So when people say 720p@60Hz, does this mean that the projector is displaying 60Hz meaning the game is only rendering 30 FPS per eye? Or are they refering actually to the game rendering 60 FPS per eye meaning the projector is displaying 120Hz?

Likewise, if its only 1080p@24Hz, is that 12 FPS per eye or is that actually 24 FPS per eye and the projector is displaying 48Hz?

The reason I ask is when gaming on my monitor in 2D, Afterburner is telling my that I get (for example) 60 FPS, but in 3D it is 30. But I assume that in 3D afterburner is really showing me FPS per eye. So assuming in a projector set up, the refresh rate is the limiting factor (meaning the graphics card will always render beyond the max refresh rate), shouldnt FPS always be half of the refresh rate of the projector?

Thanks for setting me straight.

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#1
Posted 11/25/2014 07:34 PM   
At 720p, the display is rendering 60fps per eye, alternating each frame. That means that left eye gets 1, right eye gets one, repeat. At 1080p, you would get 24 frames per eye per second.
At 720p, the display is rendering 60fps per eye, alternating each frame. That means that left eye gets 1, right eye gets one, repeat.

At 1080p, you would get 24 frames per eye per second.

#2
Posted 11/25/2014 09:26 PM   
Yeah. I think most people are pretty careful to say 1080P@24fps or 720P @60FPS. Recognizing that while it's often the norm to use HZ, in 3D's case, you need to use FPS. Because FPS is half the HZ in 3D (since it takes 2HZ to make a full frame for the brain to merge) and it can get confusing for some otherwise.
Yeah. I think most people are pretty careful to say 1080P@24fps or 720P @60FPS. Recognizing that while it's often the norm to use HZ, in 3D's case, you need to use FPS. Because FPS is half the HZ in 3D (since it takes 2HZ to make a full frame for the brain to merge) and it can get confusing for some otherwise.

#3
Posted 11/26/2014 12:51 AM   
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