Does 10bit color (HDR) gaming result in a performance hit over 8bit?

[pyrojoe34]

It is more data for the card to push and would theoretically would take more vRAM for HDR textures but is there any performance (framerate) difference? I presume not but have no idea.

 

A second separate question is would rendering 10bit video be more demanding than an 8bit video? (Ignoring the bitrate difference, say assuming the same bitrate to control for the difference?)

[Mira Yurizaki]

For games, no because video cards do all pixel work in FP32 per channel, which is a much higher dynamic range than what the HDR standards are requiring. This is why the OG PS4 can support HDR without little, if any, performance loss. Besides that, HDR has been a thing in video games since 2005, albeit they downsample to SDR earlier.

 

If by rendering you mean playing back, my money is on yes, since there's more data that needs to be processed to generate a frame.

[pyrojoe34]

1 minute ago, M.Yurizaki said:

For games, no because video cards do all pixel work in FP32 per channel, which is a much higher dynamic range than what the HDR standards are requiring. Besides that, HDR has been a thing in video games since 2005, albeit they downsample to SDR earlier.

 

If by rendering you mean playing back, my money is on yes, since there's more data that needs to be processed to generate a frame.

For rendering I mean exporting a video from Premiere or AME or Handbrake or something.

 

Anyone know of any videos that test this (like compare framerates in 8 vs 10bit games or compare 8 and 10bit video render times?) I would be surprised if there was much of a difference, if any, but you never know until you test it.

[Mira Yurizaki]

27 minutes ago, pyrojoe34 said:

Anyone know of any videos that test this (like compare framerates in 8 vs 10bit games or compare 8 and 10bit video render times?) I would be surprised if there was much of a difference, if any, but you never know until you test it.

Well, again, for games, it doesn't matter. Anything DX9 compliant or later has to render pixels in 24 bit floating point per channel. DX9.0c upped the requirement to FP32, so everything modern now renders in FP32, regardless of the output.

 

There are some early benchmarks of games with HDR on or off (like https://www.extremetech.com/computing/75570-benchmarking-splinter-cell-chaos-theory/3), but often that meant switching between SM1.1 and SM3.0, and SM1.1 is much easier to do than SM3.0

 

EDIT: I found one with Half Life 2: Lost Coast, and while there is a measurable appreciable impact, it only happened on the older cards.

Edited March 29, 2017 by M.Yurizaki

[zMeul]

11 minutes ago, M.Yurizaki said:

EDIT: I found one with Half Life 2: Lost Coast, and while there is a measurable impact, it only happened on the older cards.

that's not HDR

 

HDR, 10bit is taxing on performance

[Mira Yurizaki]

2 minutes ago, zMeul said:

that's not HDR

 

HDR, 10bit is taxing on performance

Anything at or past DX 9.0c is being rendered at FP32 per channel. HDR10 is only 10-bits per channel.

 

Considering that graphics cards are already rendering at a precision orders of magnitude greater than what HDR10 or even Dolby Vision require, there is no performance loss whatsoever going to either standard for video games vs. SDR.

[zMeul]

5 minutes ago, M.Yurizaki said:

Anything past DX 9.0c is being rendered at FP32 per channel. HDR10 is only 10-bits per channel.

 

Considering that graphics cards are already rendering at a precision orders of magnitude greater than what HDR10 or even Dolby Vision require, there is no performance loss whatsoever going to either standard for video games.

you are wrong

 

and it's not because of how many bits/pixel but because the video card has to do tonemapping twice, Windows currently is not fully HDR aware

 

http://www.pcgameshardware.de/Fernseher-Hardware-134500/Specials/HDR-Hitman-Shadow-Warrior-Resident-Evil-7-1219723/

 

[Mira Yurizaki]

Just now, zMeul said:

you are wrong

 

and it's not because of how many bits/pixel but because the video card has to do tonemapping twice, Windows currently is not fully HDR aware

If tone mapping again after rendering the final output is taxing, especially using easier data sets, then something is wrong.

[pyrojoe34]

If I understand correctly: 10bpc RGB means 30bits per pixel (8bpc would be 24bit color)?

What about RGBW displays? Are they then 40bits and 32bits per pixel respectively? Or is RGBW just a trick that doesn't actually control the white independently?

[scottyseng]

3 minutes ago, zMeul said:

-snip-

Noob, but how does HDR compare to say putting 10-bit output using a Quadro / Firepro?

[zMeul]

Just now, M.Yurizaki said:

If tone mapping again after rendering the final output is taxing, especially using easier data sets, then something is wrong.

see the graph above

 

yes, something is wrong because Windows is not yet fully HDR capable

[zMeul]

Just now, scottyseng said:

Noob, but how does HDR compare to say putting 10-bit output using a Quadro / Firepro?

how do I facepalm

[pyrojoe34]

7 minutes ago, scottyseng said:

Noob, but how does HDR compare to say putting 10-bit output using a Quadro / Firepro?

10bpc and HDR are one and the same as far as I understand. Companies that claim HDR with 8bpc are just marketing and not actually HDR.

 

Also you no longer need workstation cards for 10bpc. I believe since GTX9XX series even consumer cards are 10bpc (maybe even before that, at the very least the 10XX cards are 10bpc). The port and cable bandwidth are also factors to color depth but that is no longer a limit even at high resolutions.

[scottyseng]

2 minutes ago, pyrojoe34 said:

10bpc and HDR are one and the same as far as I understand. Companies that claim HDR with 8bpc is just marketing and not actually HDR.

Haha, that sounds good. Yeah, I've been reading the marketing hype that a fair bit of stuff is actually HDR with 8 bit (The older TVs). I just wonder why they don't just call it 10-bit color so they don't confuse people?

 

Yeah, I know some high end GPUs can do 10-bit color. I think only the 1070 and up does 10-bit out (If I remember right). Though I guess I need to get a 10-bit monitor to even use them correctly (Was planning to get one anyway for photograph / print work)

 

2 minutes ago, zMeul said:

how do I facepalm

Haha, sorry for my noobness.

[Mira Yurizaki]

2 minutes ago, pyrojoe34 said:

If I understand correctly: 10bpc RGB means 30bits per pixel (8bpc would be 24bit color)?

Yes.

2 minutes ago, pyrojoe34 said:

What about RGBW displays? Are they then 40bits and 32bits per pixel respectively?

No. The W is more than likely added by the display's image processor.

Just now, pyrojoe34 said:

10bpc and HDR are one and the same as far as I understand. Companies that claim HDR with 8bpc is just marketing.

Well no. The HDR10 and Dolby Vision spec require things beyond 10-bit color.

 

However, most of where current HDR10/Dolby Vision displays lack in that doesn't really make it as HDR as it could be is the display's brightness itself. Shoving an HDR image signal on a 200 nit display is going to make the image look like garbage.

[pyrojoe34]

4 minutes ago, M.Yurizaki said:

Well no. The HDR10 and Dolby Vision spec require things beyond 10-bit color.

 

However, most of where current HDR10/Dolby Vision displays lack in that doesn't really make it as HDR as it could be is the display's brightness itself. Shoving an HDR image signal on a 200 nit display is going to make the image look like garbage.

Can you expand on that? What other factors determine HDR other than 10-bit color? (other than obviously the display and media supporting 10bit)

Is there a minimum dynamic range requirement as well?

[Mira Yurizaki]

22 minutes ago, pyrojoe34 said:

Can you expand on that? What other factors determine HDR other than 10-bit color? (other than obviously the display and media supporting 10bit)

Is there a minimum dynamic range requirement as well?

Displays need to support the Rec.2020 color space. The highest-end color space used in high-end monitors that I've seen is DCI-P3. The other commonly used color spaces are Adobe RGB and sRGB. It also needs to support these two things that are beyond my scope of understanding: SMPTE ST-2084 Perceptual Quantizer (PQ) and a non-linear electro-optical transfer function (EOTF).

 

EDIT: This is only for HDR10. Dolby Vision has other requirements.