Flip Queue

[nsKb]

New guy here I have a few questions about Flip Queue, I apologize if this has been discussed before but I didn't see anything recent when I searched.

I'm currently running a 6950 flashed to a 6970 with Cat 12.4.

Since ATI tray tool is no longer supported does setting Flip Queue to 0 in ATI tray tool still work?

Is this setting forced so that it works across all d3d games?
I have heard conflicting reports on ATT, some say it doesn't work at all, some say it only works on certain flip queue values or that games just override it.

Does anyone have any tests to see if flip queue is being forced properly?

I have tried things like d3dantilag but its seems to not work properly with my main game (counterstrike source). I have heard about radeonpro but it seems its no longer supported so it could have the same problems as ATT.

Any input would be appreciated.

[MerolaC]

I use ATT and setting it to 0 does indeed work (also increasing it)

For your particular issue, you can set your max fps to 59.9 like this and force VSync. The mouse input lag will be completely gone and there won't be any tearing.

[nsKb]

Originally Posted by MerolaC

I use ATT and setting it to 0 does indeed work (also increasing it)

For your particular issue, you can set your max fps to 59.9 like this and force VSync. The mouse input lag will be completely gone and there won't be any tearing.

Ill try your solution but @96hz since I am on an fw900. Running less than 60fps in source will cause problems with the netcode (updaterate will be 60 instead of 67).

[MerolaC]

Ok, then, set yours to 95.9 and try. I thought you had a 60Hz display.
Should work too.
Also, thanks for noting the netcode bug, i didn't know. Sucks man

[nsKb]

I plugged in my 120hz LCD to test this since my fw900 is a PITA to switch refresh rates with.

Anyways, at 120hz (fps_max 119.9; mat_vsync 1) it felt pretty smooth, pretty similar to what I normally run (fps_max 201; mat_vsync 0). Thing when I set the monitor to 60hz and the game to fps_max 59.9; mat_vsync 1 the input lag was pretty noticeable.

So I decided to run some more tests.
120hz (fps_max 30; mat_vsync 0)- Unplayable levels of input lag.
120hz (fps_max 60; mat_vsync 0)- Very noticeable input lag.
120hz (fps_max 90; mat_vsync 0)- Slight input lag.
120hz (fps_max 120; mat_vsync 0)- Small improvement over 90fps
120hz (fps_max 120+; mat_vsync 0)- no noticeable improvements

The level of input lag at 60fps makes me think that my ATT is doing nothing and my flip queue is not being forced to 0.

This brings me back to my original question, does the Flip Queue setting on ATT even work anymore?

[MichaelTurbo]

No. The render ahead limit is hard-coded in the driver. Only games with relevant respective variable provides modification. Sucks :[

[nsKb]

Originally Posted by MichaelTurbo

No. The render ahead limit is hard-coded in the driver. Only games with relevant respective variable provides modification. Sucks :[

Is this case with nvidia or only ati?

[MichaelTurbo]

Originally Posted by nsKb

Is this case with nvidia or only ati?

AMD only.

[nsKb]

Originally Posted by MichaelTurbo

AMD only.

Thank you for the help, looks like I will be selling the 6950 and going back to nvidia.

[Falkentyne]

Originally Posted by MichaelTurbo

No. The render ahead limit is hard-coded in the driver. Only games with relevant respective variable provides modification. Sucks :[

It doesn't seem to do anything in windows 7. FlipQueueSize only worked in XP (dunno about vista).

[nsKb]

http://forums.laptopvideo2go.com/top...es-benchmarks/

This is for nvidia but this guy says that setting MPRF to 1 works. I remember reading about someone who did the same test with an ATI card and found that setting flip queue to 1 had the effect of reducing gpu load (gpu is not pre-rendering in free time so its less loaded). I will try to find that thread.

Do you guys think that if I Email nvidia or ATI they will give me a straight answer? Do you know any experts on drivers that would know this type of thing?

[rewt]

Originally Posted by nsKb

found that setting flip queue to 1 had the effect of reducing gpu load

Reducing flip queue reduces GPU load because it creates a bottleneck of sorts. The GPU gets stuck waiting on the CPU to queue up the list of commands needed to draw the next frame.

Increasing the amount of frames prepared by the CPU in advance does increase performance, but also input lag.

Originally Posted by nsKb

(gpu is not pre-rendering in free time so its less loaded)

Not quite, because it's the CPU that is doing the pre-rendering here. GPU pre-rendering (back buffering, etc.) is a different matter.

[rewt]

Something to note, beginning with nvidia drivers 300 or greater, we can no longer set flip queue ("maximum pre-rendered frames") of zero. One is now the minimum.

My theory is that Nvidia didn't like people turning it off completely and then complaining of low FPS in demanding titles.

P.S. - Between r256 and r300 nvidia drivers, the "maximum pre-rendered frames" setting did not apply to OpenGL.

[The Mac]

i sure asder00 knows

[kn00tcn]

it's not complete frames, it's draw calls (& i think they can be dropped if the game state changes enough)

those input lag tests sound like the opposite of what i see...

with vsync on:
-fps_max < 60 = little to no input lag
-fps_max 60 = little input lag
-fps_max >60 = plenty of input lag, sucks when l4d games dont have this option

this affects other games too, a trick i use is to use bandicam to cap games to 60 while vsync is on so that the input lag is reduced (for the games that seem to not internally cap)

[rewt]

I will also cap FPS a couple of frames below the refresh rate to minimize input lag, using Guru3D's very own Afterburner utility developed by Unwinder.