Opengl/sli

[whitehot78]

hello,

i recently bought cm afghanistan and cmsf with all the mods; now, i ve been playing around for a while but basically i am just trying to improve the FPS, since i'm getting poor results. I've been reading through this forum and other web resources, and i was unable to find a precise answer to this question: Does sli definitely work with this game(s)? because, i could see that sli should work with opengl, yet i havent been able to run it in this game. I use nvidia inspector to tamper the graphic options. the sli indicator gives a rather high sli rating while browsing the initial screens of the game; as soon as the 3d engine is loaded, however, sli gets switched off. what i was wondering, is if there is a particular 'sli compatibility bits' number to be set, or some other opengl option..

For now, i've been able to improve speed a little by switching the 'threaded optimization' to off. I run the latest nvidia drivers, 266.58; opengl version reported is 3.3. excuse my bad english, i hope i managed to convey what i mean.. thanks and goodbye

[Schrullenhaft]

There's no specific SLI/Crossfire support with CMSF or the upcoming CMBN. I'm not sure why SLI is turning off once you reach the 3D screens. I'll have to check with the developers and see if there is any clue as to why this may be happening.

Unfortunately I do not have an SLI setup to test this with, so I'm a bit in the dark regarding SLI and the CMx2 game engine and using the Nvidia Inspector utility to control SLI. Have you tried the built-in SLI configuration from the NVIDIA Control Panel ? These instructions on creating a specific SLI profile within the Control Panel would be one place to start.

I'm not sure which SLI method looks best or even works with CMx2:

Split frame rendering

Alternate frame rendering 1

Alternate frame rendering 2

So you may need to experiment.

Also, though newer drivers are supposed to handle this well, you may want to turn OFF the Vertical Synchronization in the 'Options' panel of CMSF and CMA games.

[whitehot78]

yes, in fact i have tried hard with the nvidia control panel before, but to no avail. what i get when enabling the sli output graph is an empty bar: this means that sli is "enabled" (since the bar, although empty, is there) but the second GPU is not rendering a single frame. only a year ago, using nhancer, we could flag some additional "compatibily bits" for sli and opengl, and with some experimenting one could usually get the second card working along the first. sadly, nhancer development has been apparently discontinued so it won't work with newer drivers. nvidia inspector also have this option, but you have to manually input a hex number which is like 0x00000000.. and i really don't have a clue here. If the devs know something it would be very helpful. also, should i make a ticket with the question?

[Schrullenhaft]

I spoke to one of the developers, Phillip Culliton, and he said the following:

CMx2 does not support SLI - full SLI support has some significant requirements and those have not been implemented in the engine. Currently your SLI setup is apparently running in "compatibility mode".

There are a few tricks scattered around for forcing "full" SLI mode on unsupported apps (like renaming the executable to the name of a supported app) but it will *not* work properly with the CMx2 graphics engine or it will not result in any appreciable gain in video performance.

So it looks like the CMx2 family, CMSF, CMA and the upcoming CMBN will NOT support SLI. It's possible that sometime in the future the graphics engine will have some updates to support SLI, but it will probably be AFTER CMBN and most of its modules come out; which is a guess at this point.

[whitehot78]

Thank you very much for your support.. i guess i'll have to bring down those detail levels then..