Unity doesn't start on Ubuntu 16.04 when SLI=on

Graphics / Linux Linux
21

Hi Rob,
What driver did you use?
Was it the beta?

22

Thanks for update. SLI Perf issue we are tracking in bug 200330395

23

I used 384.59 from http://www.nvidia.com/object/unix.html

24

It’s still not working for me.
Sometimes I get to a desktop like screen, with no icons, just boxes, but it is unusable.

25

Only new info:

Here on opensuse tumbleweed with latest updates from 19.8.2017 kernel 4.12.7 , Asus Prime 370 pro with bios 807, ryzen 7 1800 X, 32 GB Corsair Vengance 2666 @ 2933, 2x GTX 1080 KFA2 the start of a X server ( only X :0) fails with the same error as in my first post. “4486.602] (EE) NVIDIA(GPU-0): Failed to initialize DMA.”,“4486.603] (EE) NVIDIA(0): Failed to allocate push buffer”. Write me if you need new log files.

And another question is … is this info from nvidia docs ( /usr/share/doc/NVIDIA_GLX-1.0/ ) uptodate ?

33A. KNOWN ISSUES

o The NVIDIA DRM KMS implementation is currently incompatible with SLI. The
X server will fail to initialize SLI if DRM KMS is enabled.

I am unable to start tumbleweed without loading DRM KMS. In other words module nvidia_drm is loaded all the time.

26

Now i am able to start with SLI enabled X server :))
In my config ( see above ) the DMA error went away by adding ( iommu=soft ) to the kernel command line in grub2. Disabling iommu in bios also do the trick.

Best regards
Uwe

27

Any update on this issue?

28

Ubuntu desktop with SLI enabled loads up fine now (using both Unity and Gnome).

However game performance is still broken (stutters and is very slow once SLI is active).

Nvidia support have closed my ticket because “it might take a long time to fix”. Given I have the issue since April I wouldn’t hold my hopes high for SLI working with Linux games at the moment.

So still broken…