Q: Mac Pro keeps logging out since El Capitan

FIXED!!!!

Updating my Nvidia drivers the problem is fixed.

Nvidia Geforce 8800GT

Regards

The new drivers did not solve the problem for me. I am running 2 GeForce 120 GT cards.

I will try the Mission Control thing and see if that makes a difference.

The new Nvidia drivers did not solve the problem with 2 MacPro Early 2009 configurations:

=> 1 GeForce GT 120 and 1 GeForce GTX 650 Ti Boost.

=> 2 GeForce GT 120

Having the same problem with :

- early 2009 Mac Pro

- 3 x GT120

- 6 screens

- Apple default drivers

I'm logged out once or twice a day, and cannot reproduce the problem or prevent it.

Neither separate spaces/not separate spaces or using the Nvidia drivers resolved the logging out.

Stock  GT120 and a PC 5770 card in a 2009 Mac Pro

The problem occur again with the NVidia web drivers, and I don't use separate spaces.

This time, the freeze occurred while clicking on firefox to give it the focus. Firefox is on his own screen. Even knowing that, I still can't reproduce.

This tim, I didn't have the "The graphics driver has detected a corruption in its command stream" message in the console. I'm searching, but cannot found a single console message repeating at each freeze.

Same problem here: Mac Pro (early 2009), one Nvidia GT 120 and one  ATI Radeon HD 4870 each one screen.

Problem seems to be triggerable by moving the cursor almost completely to the left on the second screen. Like as if you wanted to click on the Apple menu item.

Same Problem with Mac Pro 2009.  It came with Gforce 120 card.  I added ATI Radeon a while back.  Removing the Gforce card solved the problem

Mac Pro 2009

2 quad core Nehalem

16 Go RAM

2 x GT 120 Graphic Cards

2 Monitors

Apparently after launching apps like Affinity Photo or other apps which need Graphic Cards it will log me off and I get asked to open new session with password.

Lots of problems with visual interface that bugs. After a few attempts to login and use the computer I got a Kernel Panic (grey window)

I upgraded the Graphic Cards drivers from Nvidia, but it didn’t solve the problem. I also did what JCrebbin said : disabling 'Displays have separate spaces' in Mission Control in the System Preferences (the function that allows you to have the menu bar on the top of each monitor…

Would be nice if Apple solve this issue soon…

Reading the replies, it appears that the solutions and causes are inconsistent.

I have frequently had problems over the years running 3 screens off two cards. Usually just settings and order of monitors being reset.

Perhaps the issue lies with the plist / preferences file for displays. In the past I have had to manually edit and alter permissions.

From memory, I think I manually edited the settings I wanted, then set read only permissionson the relevant plist to stop the system changing it back. This may be a red herring for a solution, but given it has been an issue with each upgrade. .. the problem may still reside in this area.

The problems seem to be how the system triggers calls to the correct display card. Either multiple spaces or the cursor near a boundary that might be considered access to the next monitor. If the system is getting confused about where and what display it should be showing, it panics.

Edit* Do the panics still happen if one desktop is mirrored to all screens?  Rather than disabling cards or monitors.

Same problem here. Early-2009 Mac Pro with two video cards.

It will 'idle' all day and all night with all apps running, but within moments of "laying on my hands" it logs me out to the sign-in screen. Oddly, the tasks that were running keep running, e.g., Time Machine backups. Could it be just that Finder is crashing?

Neither the updated web driver from NVIDIA or separate spaces setting have solved the problem here.  Still experiencing the same frequent crashes on a clean install once I plug in the third display (or even 2 displays on separate cards).

System is as follows:  Mac Pro (Early 2009) Model: 4,1 - 2.66 GHz Quad-Core Intel Xeon - 8 GB 1066 MHz DDR3 - 2 NVIDIA GeForce GT 120 512 MB cards installed. Two 20" Cinema displays and one 20WSX Cintiq attached.

Guess I'll only be using 2 displays until a fix is issued.  Hopefully it will be sooner than later.

Same configuration as must of the people here, Apple please fix it asap!!!!!!!!

JCrebbin's suggestion to turn of separate display spaces in System Preferences > Mission Control for multi-display systems seems to work, but it's only been one hour of testing. There is a price to be paid ... my second display has lost its menu bar and if another app goes full-screen the second display goes dark!