Is DSR costlier (performance-hit wise) than simply running at 4K?

[Kevin Weinberg]

Suppose I bought a 4k TV. Would the cost in frame be greater, equal, or less than merely running something with DSR?

I only ask because DSR -> 4k on a 1080p TV is a tremendous performance hit on my SLI 780s

But I was wondering if I bought a 4K TV if performance would be mostly the same as using DSR.

I tried Googling this question and could not find an answer, and so I apologize if this has been asked already.

 

[TheDualshock]

When the graphics card are rendering the game with 4 times the pixels, then down-scaling it to 1080p. Theoretically, it should have the same impact but I'm not aware of any tests done about it yet.

 

[ShadyHamster]

You are likely to see better performance using a native 4k res screen using using DSR/VSR to downscale to 1080p.
My theory is that using DSR/VSR the graphics card has to first render in 4k then downscale compared to just rendering 4k at native res.
I doubt the performance hit would be much, a few fps maybe.

 

[photonboy]

You are likely to see better performance using a native 4k res screen using using DSR/VSR to downscale to 1080p.
My theory is that using DSR/VSR the graphics card has to first render in 4k then downscale compared to just rendering 4k at native res.
I doubt the performance hit would be much, a few fps maybe.

You are correct.

The game is rendered at 4K which is very costly, then a small additional cost of down-scaling is added.

*Thus the experience at native 4K will be nearly IDENTICAL.

There ARE some games that are less demanding which will run acceptably. You also have a few choices when it comes to the DSR settings so you can experiment.

I ran Torchlight 2 on a single GTX680 card at 4K. It managed above 60FPS despite the less GPU power. It's worth noting that I ran out of VIDEO MEMORY and the frame rate plummeted; even with 3GB (same in SLI) you may have issues in more demanding games at 4K.

(It's worth noting that 4K might not benefit much visually if not sitting close enough, especially if on a 1080p HDTV and downscaled. It's also important to ensure you are in a "gaming" mode for the HDMI input to prevent video rendering and thus additional lag by the HDTV)

Summary:
a) 4K native vs 4K downscaling is similar (downscaling just slightly more demanding)
b) Some games will run fine at 4K 60FPS
c) 3GB of VRAM will be insufficient for some games at 4K
d) DSR has several choices that can affect performance (In the NVidia Control Panel)

 

[photonboy]

In case I wasn't clear, you can try various upscaling options the smallest for example is 1.2X native.