I bought myself a Lenovo Y510P with two GPUs (GeForce GT755M), because I read some articles that SLI is working (my fault that I didn’t pay attention that all were desktops). Since Chapter 29 and more precisely this ftp://download.nvidia.com/XFree86/Linux-x86/334.21/README/sli.html states that Mobile GPUs aren’t supported I attempted only a few times trying to have SLI working (ending with kernel panics due to “Unable to dereference a null pointer”).
My question is, is there going to be any future support for SLI and MultiGPU in mobile chipsets or I have to stick with a supported OS ?
Would love to know this myself since I’m in the same situation. I’ve seen several posts of people claiming it worked. One post here states it causes errors with sleep.
I’ve got the 750M GPUs. Why are the 755 ultrabay cards cheaper than the 750s by so much?
Since other users claim that it can partially work (as pointed by clytle374), I compiled the latest 3.14.0-rc8 kernel, patched the 334.21 driver in order to install it and tried the SLI. This time there was no kernel panic due to a "Unable to dereference null pointer at ", but the whole screen got black and the log just said to consult Chapter 29 from the NVIDIA driver documentation because SLI could not start (read that via SSH-ing into the box). Would be nice to have at least a reply from an nVidia representative on this matter.
P.S. I can provide any kind of logs if needed, but since this is not officially supported I won’t attach them without any request to do so.
On Gentoo here and am also will to help with debugging.
The new 337.12 still won’t run in SLI mode and that statement for Mobile GPUs is still in the Readme. I have no idea what the difference between mobile and desktop chipsets is (other than the obvious ones ofcourse), so some insight on this would be highly appreciated.
Until SLI performs properly under Linux? There’s no point in them supporting mobile SLI… I’m running Dual GTX480’s in SLI and using -sli=on or -sli=afr or -sli=auto causes it to use Alternate Frame Rendering which causes my framerates to drop by 50% and it doesn’t utilize the second card at all…
Using -sli=sfr though? The first card only works… no activity on the second card… so supposedly right now in Linux? The only thing suppored with SLI is Doom 3, Quake 4 and ETQW… otherwise it won’t work with just basic settings. :(
I’ve filed an nvidia “ask a question” and talked to a Linux Driver developer about the issue and submitted my logs so hopefully it’ll help bring some life to SLI on Linux. :)
Hopefully, because with Unreal Engine 4.1 coming over natively on Linux/SteamOS we’d need all the GPU power we can get and I personally think that SLI is the way to do it, as my performance under Windows is through the roof :)
It would be cool yeah for SLI to come to Linux… but ultimately? The Linux driver dev team for nVidia is quite small compared to the Windows driver dev team, which is probably why the Linux driver updates take much longer to progress and even technologies like SLI isn’t anywhere near as advanced as the Windows driver versions.