SLI Users?

[Aza]

Are there any other SLI users running linux? im using 2x 2gig gtx670's but not no performance gain under linux and in most cases severe performance drops. The only SLI Rendering mode that seems to work is SFR all others drop me to 80 or less FPS? Should i give up on sli and buy a GTX Titan? or are they not supported in linux drivers yet?

[Toquita]

Now, hold your horses man! We're only starting to live the Linux Gaming dream!

[Aza]

Well there are some GTX Titans floating around cheaper then 690's so if im going 1 card thats the way i would want to go. Catch ma drift?

[blackout24]

I have heard that we will see some Linux GTX Titan benchmarks soon. There might already be a driver but I don't think 313.18. NVIDIA is very quick to support new hardware for Linux. Unfortunately I have no experience with SLI and don't know if it might require a little tweaking of your X.Org Conf file to get it work properly.

My distros Wiki says this:
https://wiki.archlinux.org/index.php/NVIDIA#Enabling_SLI

[Aza]

Yea I've placed more hours than i dare count into tweaking it and trying different distro's but SLI as a platform just seems to lack support on linux. So i may just go all out on one card unless someone can provide me a miracle tweak that i've missed?

[blackout24]

Have you used the advice from the Arch Wiki once? Also what CPU do you have? SLI requires some overclocking to get the most out of it. It could be that it is slowed down by the CPU switching frequencies very often. Have you tried to set your CPU to "performance" once to clock it at max. speed all the time?

[Aza]

Yea currently runninc OC, and under full performance profiles system specs are as follows: CAS]: Thermaltake level 10 GT
[W/C]: Corsair H100i
[CPU]: i7 3770k oc 4.8ghz
[MOB]: ASUS P8Z77-I DELUXE
[RAM]: 32gig corsair
[GPU]: Galaxy GTX 670 2gig x2 SLI (Currently having issues setting up under linux)
[PSU]: Corsair tx850
[SSD]: 256gb
Have settled on Ubuntu 12.04 LTS 64bit, Basically due to laziness and couldn't quite get comfortable with arch.

[blackout24]

Try installing "cpupower" and do "sudo cpupower frequency-set -g performance" it should clock every of the 4 cores and 8 threads at 4.8 Ghz.

Also see if the link I posted offers any tweak that you might not have tried yet.

Here is some handy information on how to find out the real clockspeed in Linux. cpupower frequency-info will only display the speed steps.

https://bbs.archlinux.org/viewtopic.php?id=158463

[Aza]

Cheers mate will go through it a bit more thoroughly in the morning when Im a bit more focused and will report back.

[blackout24]

Also make sure you are on 313.18 which is the latest driver.

[Kano]

Best is to get rid of SLI, i only have got a GTX 295 to try now but multigpu mode only increased speed with the special Doom3 hack for doom3 or dhewm3. One single gpu is the way to go. Crossfire is the same crap on Linux - you have to be lucky when it does not show worse performance (like with 2x HD 5670 in SS3) when enabled but speed increases are very rare.

[Laika]

Only thing you want to do with those Graphic cards is run 4 or 8 displays. 24 inch :P
And trust me. Once you have those set up. You don't want to go back.

[moontabin]

I am having issues getting Steam to start on my Linux system with SLI enabled. If I turn it off it works fine but if I have it enabled I cannot load the program or the GUI for Steam. Any ideas?

[ThE_MarD]

Heyyo,

To the OP? I hope you don't buy an SLI setup for use in Linux (for now that is... SLI profiles, or heck, SFR and AFR might work in the future)... Multi-GPU is the same thing as SLI... SFR runs either the same as a single card or rarely better... The GTX Titan would have the same preformance issues until proper SLI Profiles are incorporated into Linux, or SFR and AFR actually work on games without SLI Profiles... Right now only ID Tech 4 Engine based games (Doom 3, Quake 4 & ETQW for example) can function under SLI / Multi-GPU in Linux properly AND that's only if you make your own custom profile because as of this post? beta driver 334.21 doesn't come with profiles at all... you have to make them. :\

sudo nvidia-xconfig --sli=sfr

and for GTX 690 or other multi-gpu cards...

sudo nvidia-xconfig --multigpu=sfr

(You can do it as on, auto or afr but they tend to have incredibly terrible performance in Linux for now...)

I'm sure as time goes on? nVidia will give Linux the same SLI love they've given windows and we shall see proper SLI profiles and proper gains even in games without any SLI profiles.

I've been testing a bunch with Xubuntu 14.04 beta2 using Geforce 337.12 beta drivers using GTX 480 SLI in 2-way configuration... like I said, I get the same performance as 1 card in pretty much everything, rarely do I see my SLI Visual Indicator show that it's working with both cards.