Pre-Rendered Frames (scam!?)

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chenifa
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Re: Pre-Rendered Frames (scam!?)

Post by chenifa » 29 Mar 2021, 13:21

RealNC wrote:
29 Mar 2021, 10:05
The "ultra" setting basically acts like a prerender queue of 0.
Are you sure about that? If you swith from llm off to ultra, Max pre-rendered frames setting goes from application controlled to 1.
I don't know why this would help in situations where the GPU isn't being maxed out though.
Well, if in fact the queue goes from 1 to 0, there would be a difference no matter if the GPU is maxed out. Even if the gpu renders fast, the cpu works on the next frame in the meanwhile. -If ultra stops that behaviour it would make a difference.

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RealNC
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Re: Pre-Rendered Frames (scam!?)

Post by RealNC » 29 Mar 2021, 14:13

chenifa wrote:
29 Mar 2021, 13:21
Are you sure about that? If you swith from llm off to ultra, Max pre-rendered frames setting goes from application controlled to 1.
Yeah. It also does that when you set LLM to "on". The point is when that one pre-rendered frame is going to be submitted. With LLM "on", it's gonna be submitted as soon as possible. With "ultra", as late as possible, thus acting as if MPRF was 0.
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chenifa
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Re: Pre-Rendered Frames (scam!?)

Post by chenifa » 31 Mar 2021, 12:43

Got it, thanks for explaining!
Well, maybe if someones bored they can test ultra vs off in cpu bound games and tell me if I'm placeboing. For me it feels very different.

ELK
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Re: Pre-Rendered Frames (scam!?)

Post by ELK » 05 Apr 2021, 20:42

As far as I am aware pre-rendered frames is a bogus setting as game engines control the queue size. Your tests in witcher 3 suggest that pre-rendered frames does something, but maybe something else is causing the lag?

Why in the elder scrolls IV: oblivion when using a framerate limiter (SSYNC in my case) does changing from low to ultra make a huge difference in input lag. The input lag is so low that even 30fps is playable. This does not apply to any other game. Oblivion was notorious for having to change pre-rendered frames from 3 to 1.


EDIT: I can't reproduce the results. Oblivion seems to have incredibly low input lag unless vsync is enabled alone. vsync + 35 fps limited results in a constant 35fps@60hz with no tearing for some reason.

MatrixQW
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Re: Pre-Rendered Frames (scam!?)

Post by MatrixQW » 06 Apr 2021, 05:32

chenifa wrote:
29 Mar 2021, 06:40
Even more dubious is that I can tell the difference between off + max pre-render 1(set in nvinspector) and ultra in a game like kovaak, which doesn't max out gpu at all.
RealNC wrote:
27 Mar 2021, 08:12
I don't know why this would help in situations where the GPU isn't being maxed out though.
I'm confused. Battlenonse video about low latency shows that 'ultra' increases input lag if not gpu bounded but now Chenifa is saying the opposite.

https://www.youtube.com/watch?v=7CKnJ5ujL_Q

Note: According to Nvidia, LL only works with DX9 and DX11.
Last edited by MatrixQW on 06 Apr 2021, 06:17, edited 1 time in total.

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Re: Pre-Rendered Frames (scam!?)

Post by MatrixQW » 06 Apr 2021, 05:54

I just tried something:

NVCP Low Latency 'off' and then I set NV Inspector MPRF '1'.

When I check NVCP, LL is still 'off'. Maybe this screws things and it needs to be set to 'on'.

Also, would having G-Sync disabled or enabled affect the behaviour of LL?

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Re: Pre-Rendered Frames (scam!?)

Post by RealNC » 06 Apr 2021, 14:48

MatrixQW wrote:
06 Apr 2021, 05:54
Also, would having G-Sync disabled or enabled affect the behaviour of LL?
Not directly. If you enable gsync and use ultra LL, then you get an automatic FPS cap that's somewhere between -6 and -2 FPS below the current refresh rate, depending in what that refresh rate is. At 144Hz, you get -6 (138FPS cap). At 60Hz, you get -2 (58FPS cap.)

Other than that, ultra LL does the same thing as without gsync.
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blackstorm82
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Re: Pre-Rendered Frames (scam!?)

Post by blackstorm82 » 08 May 2021, 04:01

RealNC wrote:
06 Apr 2021, 14:48
MatrixQW wrote:
06 Apr 2021, 05:54
Also, would having G-Sync disabled or enabled affect the behaviour of LL?
Not directly. If you enable gsync and use ultra LL, then you get an automatic FPS cap that's somewhere between -6 and -2 FPS below the current refresh rate, depending in what that refresh rate is. At 144Hz, you get -6 (138FPS cap). At 60Hz, you get -2 (58FPS cap.)

Other than that, ultra LL does the same thing as without gsync.
Then can I assume that the LLM "ultra" of the asynchronous monitor operates at zero in the absence of GPU BOUND?

I wonder if this function called maximum pre-rendering works even in non-GPU BOUND situations.

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Re: Pre-Rendered Frames (scam!?)

Post by ELK » 12 May 2021, 06:03

What is the difference between reflex and null?

1 pre-rendered frame
cpu generates next data when the previous data has been used, attempts to keep a buffer of 1 full

null
cpu generates next data when the previous data has been used

reflex
cpu generates next data after frame completion?
cpu generate next data after frame displayed?
basically cpu does some kind of idling THEN cpu generates next data?

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