First off, I've got 4 Gb of RAM running on a Dell XPS 410 from 2006 using a 2core duo CPU. Centos 7 is, of course, 64-bit.

I'm getting a recurring error causing a 3-5 minute halt in all operations while the error logs are written. Seems to be caused by Firefox and/or ALT-Tab application switcher.

I've disabled all extensions in Firefox.

Nouveau card driver is targeted at nVidia chipsets NV40 and above. My card is an NV44. [10de:0165]
Quadro NVS 285

Here's a couple of excerpts from the messages log:
kernel: nouveau E[gnome-shell[3017]] fail ttm_validate
kernel: nouveau E[gnome-shell[3017]] validate vram_list
kernel: nouveau E[gnome-shell[3017]] validate: -12

and,

Dec 15 11:33:08 [hostname] gnome-session: nouveau: kernel rejected pushbuf: Cannot allocate memory
Dec 15 11:33:08 [hostname] kernel: nouveau E[gnome-shell[3752]] fail ttm_validate
Dec 15 11:33:08 [hostname] kernel: nouveau E[gnome-shell[3752]] validate vram_list
Dec 15 11:33:08 [hostname] kernel: nouveau E[gnome-shell[3752]] validate: -12
Dec 15 11:33:08 [hostname] gnome-session: nouveau: ch0: krec 0 pushes 1 bufs 28 relocs 406

I've googled, but found little to go on.

I found the Nouveau website, but their troubleshooting is difficult for me to follow. For example, "ensure normal nvida device drivers are not being loaded." I just installed 7, so I would have no idea how to install nvida drivers. This type of thing. Never the less an attempt to do so came up negative. I queried yum to see if they were installed. Not sure if that is correct strategy.

I don't see any forums on the Nouveau website.

I ran a similar request on Centos forum about a week ago, and got no action. Maybe because first response was asking how much RAM, and that kicked the post out of the "yet to be worked" category (??)

In summary, I need help determining cause of problem and solutions.

Thanks,

1. You can use the nvidia driver for your graphics card. The nouveau driver must be unloaded prior to installing the nvidia driver.