Q: Mac Pro keeps logging out since El Capitan

Sorry, I spoke too soon. It started crashing again after a few hours.

After suffering logouts every few minutes with 2xGT120s and 2x24" Apple displays on an early 2009 MacPro

It appears that

11.11.2 Beta 3 released 11/10/15 (15C40a) combined with the latest

Nvidia drivers 346.03.04b01 and

CUDA driver version 7.5.21

has fixed the problem for me.

Alive again!

Mac Pro early 2009  16GB, 4 GTI 120 graphic cards, 3 in used with 3x24 Apple Monitors.. one on each card (1 card unused but plugged in).

Installed:

OS X 10.11.2 beta 3

Using OSX default graphic driver (Nvidia Driver Manager doesn't not allow this version of OS to use its driver... not yet available I guess) but regardless it's stable with the default graphic driver from Apple!

Mission Control: Displays have separate Spaces - checked!

Works flawlessly - so far  (1 hour of usage with multiple firefox windows/tabs, was not able to do it before this update) ... hopefully this build is stable when it's released.

Keep the posts coming when this version is released.

Good luck fellow Mac Pro early 2009 faithful...

Use  Nvidia Web Driver - 346.03.04b01, it works perfectly and allows the Nvidia web driver with the latest OS 10.11.2 Beta 3.

Exercising a Mac Pro early 2009 with two GT120 and NO separate Spaces more than 14 hours without any problems!

I'm having the same problem.  I spent a ton of time on the phone with Apple technical support.  Of course, they didn't know about the fix mentioned below.  I will go ahead and try that and report back.

Hi.  I am having the same problem.  2009 Mac Pro with 3 monitors.  I have wiped out my OS and get back to Yosemite.  I wanted to confirm with you that your fix has continued to work for you (before I go ahead and upgrade again to El Capitan).  Really appreciate your feedback.

24 hours later and everything has been working fine. No logouts.

Previously it failed every few minutes. 

I have been running the latest beta of Mac OS X all day with 2nd monitor with no problems.  Yah finally I can use my 2nd monitor and code efficiently   Knock on wood!

Thanks Apple,

Kenneth

Now running flawless for 36 hours!

So, pporzer, is that 36 hours with Separate Spaces enabled., or still running with it unchecked? That toggle is key to usability IMO – enabling separate spaces lets menuing be available on all screens.  The way it oughta be.

Yes, I have been working with "Separate Spaces" Disabled. I'm no trying to turn the switch  ON and can hopefully report soon!

First results are promising. I'll now exercise moving movies and photos and other stuff around, having now 20 windows in both screens open. Let's see!

For what it's worth I've been running with separate spaces enabled for over 48 hours with no problems.   

Can anyone share insights regarding current success/failure with more than 2 monitors on EC?  I reverted to Yose because I could not use EC in any config with more than 2 monitors. I did not have a problem with 2 monitors on one card.  Had big problem trying to use two cards with 3 or 4 monitors.  I do not want to spend $$$ buying new cards.  I'd rather buy a new system with a warranty. But for now, Yose is doing the job, crappy as it is, crawling along on my Mac Pro 3.1 8 core. Strange that my little 13" Air on EC is now out performing my big, bad, Mac Pro which has better specs.

What cards do you have?

I have no problem with one GT 120, one PC 5770 with Nvidia drives and displays use separate spaces not checked.

I have not seen a solution for using two GT 120's