Zorin 15: NVIDIA + AMD = Login Loop, Worked OK in 12.4

Hello!

Machine: Dell Precision T3600; Xeon E5-1620
(2) GPUs: AMD FirePro V4900 + NVIDIA GeForce 8400GS
The FirePro is driving my main display and the GeForce is driving two supplemental displays
(I know this is a bizarre setup but it's hobbled together from spare parts)

While everything worked right out of the box in Core 12.4 (even in the installer), I cannot for the life of me get these two GPUs to cooperate in 15. I end up in that login loop right after the decrypt prompt. Each card works fine on its own, and this only happens when they are both present. Uninstalling the NVIDIA drivers brings back the AMD GPU but no output is supplied to the NVIDIA displays.

I have spent days on this literally doing everything I've come across and have probably ended up reinstalling it all literally a dozen times along with every driver I could install. It really seems like an NVIDIA issue, and based on the scores of issues I've read with Ubuntu NVIDIA drivers and their general lack of reliability, I believe that's where the problem is.

I've gone back to 12.4 and everything works fine, although in the past when I've installed the proprietary NVIDIA drivers, I've also ended up in the boot loop situation. However, even using the free drivers in 15 results in no output from the GeForce. I've read that the 8400GS isn't supported after v340.96. I've tried installing an older version but found it isn't compatible with anything past XServer 1.10.

Any ideas on what I can try? If I noted everything I've already tried here, this post would go on forever. Suffice it to say it's the first several pages of every forum that hit on variations of this issue.

Is this the end of the line if I need an older driver but can't run it because XServer is too new? I don't think it's practical to roll that back. I hope there's a way, but for now it's looking like I need to make the decision to either stick with Zorin 12.4 or go out and buy a new video card. I certainly won't be going back to Windows (although everything obviously worked with Win 7 with little effort).

I've only been into Linux for about 6 months and am desperately trying to get everything working here so I can ditch MS once and for all, so I'm obviously still learning. Thanks so much in advance for your help!

Zorin has made computing a pleasure again, after 5+ years of banging my head against the wall with Win 8/8.1/10 and some of the mind-boggling things I've seen make to final release. A huge kudos to the folks who made this possible, this will disrupt the industry eventually.

Have you tried running the nvidia cards with just the bog standard nouveau? Basically don't check the bit about installing graphics and other drivers at point of install. Also have you tried using x r and r?

I should have mentioned that the Nouveau drivers work fine driving the 8400GS so long as the AMD card isn't present. There is no output from the 8400GS when the AMD is present. The card is detected in lspci. I'm thinking this is probably the closest I've come to a resolution: figuring out why the AMD card causes the NVIDIA one to go MIA with Nouveau. And yes, I've been through several things in xrandr and can't seem to get it. I'll also add that I've tried all three install modes (regular, safe, and NVIDIA modern).

Wow, indeed an unusal setup.

For starters could you post the output of inxi -Gx ?

Its also important to mention here exactly how the cards connect to the cards, what display port is it and are you using any converters?

I am presuming you would have to create a custom /etc/X11/xorg.conf file.

It really seems as though Ubuntu and NVIDIA really don't work well together.

I tried NVIDIA version of Feren O/S (Ubuntu and Linux Mint based) and even that would not load NVIDIA drivers for me - due apparently to Kernel and Xorg issues, apparntly. Neuveau, however, works just fine on my NVIDIA cards.

I've now found out that my NVIDIA cards were too old for the NVIDIA drivers available to Feren O/S and probably Zorin 15.

NVIDIA driver 304 is a no go - it is an old Windows XP machine, after all.

Neuveau works just fine, fortunately.

Update: I ended up reverting back to 12.4 and have everything (generally) working great. In 15, I wasn't using any adapters or anything. I did also have a DisplayLink screen that was causing further issues with the setup and I've removed that from the equation.

I was able to get all of the displays functioning in 15 with Nouveau, but it was unusable as any sort of video (like YouTube) must have been rendering at about 5FPS (despite the 60Hz refresh rate) and the fans sounded like they had COPD. I plan on eventually upgrading to a single video card (certainly NOT anything NVIDIA) that can run 4 displays. My experience with the AMD is that it works absolutely flawlessly, so I'd love any suggestions on a reasonably-priced AMD card that can run 4+ displays (one in 4K). I just like to hang onto old hardware as long as I can if I can make it work.

The only issues I now have with 12.4 is that occasionally the two displays on the NVIDIA card have a glitch where they seem to both be trying to display both outputs simultaneously. It's very strange. When you interact with the display, you get bits and pieces from both displays rapidly superimposing on themselves. Going into displays, turning one of them off (or changing the resolution) and then changing it back usually resolves it. Oddly, this doesn't happen every time I boot it.

The other issue is a blank screen (but with movable mouse pointer) when resuming. This only happens when the main display goes to sleep (it has a glitch where it shuts itself off for not detecting signal even though signal is there). I have everything set to stay on 24/7, but this particular display just has a mind of its own. It also insisted on only outputting at 24Hz, I had to tweak the xrandr quite a bit to get it to 60, but it's fine now there.

Everything else is working great. I finally got VNC and Samba working with a client running 15. Very happy with it. I'll stay with 12.4 on my server until I can find a bargain on a modern video card.

Finston Pickle wrote:It really seems as though Ubuntu and NVIDIA really don't work well together.

I tried NVIDIA version of Feren O/S (Ubuntu and Linux Mint based) and even that would not load NVIDIA drivers for me - due apparently to Kernel and Xorg issues, apparntly. Neuveau, however, works just fine on my NVIDIA cards.

Yes, I've had nothing but issues with NVIDIA for many years across all platforms. I'm not sure what's going on with them. Maybe a modern video card works fine. If they flat out said it wasn't supported, I'd accept that. It's the fact that they claim compatibility (and even that it's been tested) when that's clearly not the case. And trying to get support from them is almost as frustrating as Microsoft with the canned "didn't you read this irrelevant article with broken links?"/"did you reboot your machine?"/"it's not us, it's them"-type responses.

That's why I love Zorin so much. They actually take accountability and continuously improve. Any flaws I've come across have been from the Ubuntu underpinnings itself so I can't fault them for that (other than Zorin Connect, but once again, they are working on it and it seems to work for 99% of people out of the box). I have no intentions of ever returning to Windows (other than the VM I run to be able to offer support). In the future, I'll be investing in hardware made by manufacturers that support and care about Linux and recognize that it's the future.

I find it interesting that you too have had issues with nVidia - my best man has always had AMD - I have always had nvidia - apart from the onboard graphics that came with the last rig and I struggled to get it to work properly, even in Windows 7 - So I bought an nvidia GT620 - then Zorin 15 came out - it could not handle the latest drivers - Zorin 15 demands cards that support nvidia 410 at the least which is a GT710 - so I upgraded to a Zotac 1030 nvidia card - no issues, and I got proper screen refresh rate. That said before I got my replacement viewsonic which I donated to family member I was given a 32" Samsung TV which hurt the eyes and was only reporting 30 Hz. Now with the replacement Viewsonic on VGA (that's because I prefer SoundBlaster Audigy Rx to HDMI with recently purchased Logitech Surround sound system).