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SH64
08-25-06, 11:49 PM
After some searching & asking i found out that the mouse lag issue that incorporates with SLI might be related to the AFR/AFR2 rednering modes mainly.
which means that even Crossfire might be suffering the same issue.

with AFR there seems to be a latency issue associated with that mode of rendering. the more frames alternated the more severe the implifications of it would be (2 in SLI , 4 in Quad).
thats why in some games you get the feel of playing @20fps while your framerate is actually 40fps.

to test this i took 2 games for a spin .. Quake4 & BF2.

Quake 4 uses AFR (AFR for SLI & 4-way AFR for Quad). i picked a savegame where my framerate hovers around 40-60fps on 4-way AFR & forced 4-way SFR instead & heres what happens :
with SFR the game somewhat ran "smoother" although framerate is much less than AFR!
AFR , framerate =~ 45+fps
SFR , framerate =~ 30+fps

next is BF2 which uses AFR2 for SLI & AFR-of-SFR for Quad SLI.
the mouse lag issue here is less noticable for me since it uses AFR-of-SFR perhaps (higher framerate most of the time & only 2 frames to be alternated .. might be more obvious with AFR2 on SLI configs) & again i forced 4-way SFR & i got the same result as above!
@30fps the game is pretty playable under AFR-of-SFR which is cool , but again under 4-way SFR the game is playable too althought framerate sometimes hovers around 20fps or less! (overall though AFR-of-SFR is what i prefer).

so .. people who suffer this issue might need to go ahead & test that & give feedback if possible.
pick a game that uses AFR or AFR2 & force SFR on it & see how things go & post your findings if you like so we can confirm this issue.

Note : If you dont get any mouse-lag issues with SLI/Quad SLI then this is not for you .. move along

JaxMacFL
08-26-06, 09:50 AM
I read and now utilize a tip where to minimize mouse lag, go to Nvidia Control Panel>Performance & Quality settings>Additional Direct 3d settings>under Advance 3D settings, set Max frames to render ahead to '1'. I use AFR with GTA:SA, SFR with Tiger Woods 2K6 and AFR2 with NFSHP2 . All run really smooth with no noticeable mouse lag.

Burnt_Ram
08-26-06, 09:52 AM
hmmmm, interesting ! i'll have to try this out. i use AFR/AFR2 exclusively. have tried SFR, but the frame rates are very low compared to AFR/AFR2.

Burnt_Ram
08-26-06, 09:54 AM
I read and now utilize a tip where to minimize mouse lag, go to Nvidia Control Panel>Performance & Quality settings>Additional Direct 3d settings>under Advance 3D settings, set Max frames to render ahead to '1'. I use AFR with GTA:SA, SFR with Tiger Woods 2K6 and AFR2 with NFSHP2 . All run really smooth with no noticeable mouse lag.
i recently tried this out with COD2 which i use AFR, and it did smooth it out alot. still some lag, but ALOT better than before :)

SH64
08-26-06, 01:36 PM
I read and now utilize a tip where to minimize mouse lag, go to Nvidia Control Panel>Performance & Quality settings>Additional Direct 3d settings>under Advance 3D settings, set Max frames to render ahead to '1'. I use AFR with GTA:SA, SFR with Tiger Woods 2K6 and AFR2 with NFSHP2 . All run really smooth with no noticeable mouse lag.
It does make things better in some cases , but has no effect on others .. Quake 4 for exmaple wasent affected no matter what max frames i set it to (perhaps only a slight difference).
however with SFR its obvious & you can feel it instantly.
besides , the objective of this thread is to recognize the AFR issue ;)

thanks for the contribution though .. i'll try messing around with that option more & more as i test other games.
oh & any more tips are welcome :D

AMC_Duke
08-26-06, 03:20 PM
It does make things better in some cases , but has no effect on others .. Quake 4 for exmaple wasent affected no matter what max frames i set it to (perhaps only a slight difference).
however with SFR its obvious & you can feel it instantly.
besides , the objective of this thread is to recognize the AFR issue ;)

thanks for the contribution though .. i'll try messing around with that option more & more as i test other games.
oh & any more tips are welcome :D

yeah Quake 4 is one of the best exeples for mouse lag its just =( i tryed afr sfr and not mutch difference do you guys think this crap can be fixed by nvidia or is it hardware side problem ?

SH64
08-26-06, 04:19 PM
yeah Quake 4 is one of the best exeples for mouse lag its just =( i tryed afr sfr and not mutch difference do you guys think this crap can be fixed by nvidia or is it hardware side problem ?
Its a multi-GPU rendering issue or limitation if you will .. i dont see a possible way for drivers to fix it .. at least thats my guess.
theres a possibility that DX10 which is supposed to remove the overhead in AFR scaling for Quad-GPUs to fix or probably reduce it to some degree.
again all this is pure speculation.

AlexDP
08-26-06, 08:32 PM
According to something I read somewhere from NVIDIA themselves, the CPU is also important in being able to use AFR correctly with minimal lag. The CPU has to be very fast in order to supply the data to the GPUs fast enough. If the CPUs not fast enough then it becomes the bottleneck and hence lag when using AFR. If im not mistaken I think the recommendation was to turn up the reso. and increase the visual settings in order to push the work back to the GPUs...

jAkUp
08-27-06, 12:13 AM
I also noticed severe mouse lag in Fear, I believe Fear uses 4 way AFR.

My FPS would be like 40fps, but the mouselag is terrible, caused me a few deaths I think :( I might try SFR to see if anything changes

The sad thing about this whole ordeal is that with DX10 we may see the death of SFR games.

SH64
08-27-06, 10:04 AM
I also noticed severe mouse lag in Fear, I believe Fear uses 4 way AFR.

FEAR uses AFR-of-SFR as most other D3D titles. Nvidia alreay stated that : 4-way AFR is not possible for current D3D titles until DX10 comes out due to a limitation in the DX9 API.

as for the high res suggestion , well i'm already playing @1600x1200,4AA+ .. in Prey for exmaple when i went to 1600x1200,8xAA the mouse-lag was so horrible is places where framerate reaches 35fps so i had to revert back to 4xAA.

jAkUp
08-27-06, 10:06 AM
Whoops yea your right it does use AFR of SFR.

The mouse lag is still really bad though, it seemed so bad the other day I loaded up fraps, but my framerate was very good.

As for res, I am playing at 1920x1200 4x/16x. Prety was bad sometimes too, but 10x worse with Vsync.

SH64
08-27-06, 10:10 AM
Whoops yea your right it does use AFR+SFR.

The mouse lag is still really bad though, it seemed so bad the other day I loaded up fraps, but my framerate was very good.

As for res, I am playing at 1920x1200 4x/16x. Prety was bad sometimes too, but 10x worse with Vsync.

Still bad even with 4-way SFR ?? did you make sure it was forced ?? (the load balance should show 3 horizontal lines moving ..)

jAkUp
08-27-06, 10:12 AM
I havent tried it yet :o I'm going to try 4 way SFR today.

SH64
08-27-06, 10:14 AM
Gonna try that aswell & mix it with some different "max frames to render" values.

AMC_Duke
08-27-06, 02:35 PM
I tested some q4 sceens with some settings and it seems like AA makes a big deal in this lag issue i forced higher resolution without aa that i get about 40 fps so i checkd and the mous lag was defenitly les with out aa activated then with

Check

40 fps SLI + 4 x aa = lag
40 fps SLI w/o aa = much less lag

give it a try

SH64
08-27-06, 03:13 PM
Hmm it does sound logical as the MSAA put more strain on the memory subsystem & thus more data per frame , but in FEAR i'm already playing w/o AA since i'm using SS (1600x1200,noAA,16xAF,SS). still .. the bad lag is there :thumbdwn:

jAkUp
08-27-06, 06:52 PM
Ok, SFR maybe seems a little smoother in the case of fear, but the lag is still noticable.

SH64
08-27-06, 06:57 PM
Ok just tested FEAR with SFR & seems SFR is not compatible with that game so its no use for testing. tried with max frames @1 .. same deal.

your best bet is to play with the built-in profile & setting the max frames to 1 ... it seems to help things a bit , but again anything lower than 35fps & the mouse-lag is obvious to me.

EDIT : haha we posted at same time~! :D .. i find SFR not compatible with FEAR at all though. (framerate goes up & down for no obvious reason).

jAkUp
08-27-06, 07:46 PM
Yea framerate is very bad in SFR fear, but when I lower the AA/AF settings, it seems to be a little smoother overall.