Graphics card issues with new system build

[Paul Goyette <paul%whooppee.com@localhost>]

OK, I'm getting frustrated as hell.  :-)

I've got my new system built, and managed to get the dmesg uploaded to
NYCBug ...

It's got a AMD Ryzen 9 7950X3D CPU, which has internal video configured
as acpivga0 - I disable this (using userconf) when I boot because I need
to use the older-but-supported GeForce 730 graphics card.

Boot comes up normally and starts X (via xdm).  However, I'm getting the
following message logged on the console.  As far as I can tell, they're
logged when switching from the xdm console session to a non-X session;
but it is difficult to be certain of the timing.

	nouveau0: error: DRM: core notifier timeout

I also sometimes get

	nouveau0: failed to idle channel n [user]

when stopping xdm.

During normal operation, things are OK, other than "jerky" cursor
tracking.  Most often, the cursor "sticks" in one spot for a few
seconds, and then continues to track.  "One spot" is very often, but
NOT ALWAYS, at a point where the mouse icon needs to change (ie, it
enters or leaves a window or button, etc.)

After a while, the system just hangs (suspicion: it's hitting one of
the core notifier timeouts, and hangs forever rather than time-out).
I can still access the machine via network log-in but cannot get
anything done "locally".  At this point I can't even switch to the
non-X console sessions.  The hang-time varies, but comes much sooner
when there is heavy system activity - like build.sh - going on.  It
even comes, however, with no activity at all - just staring at the
screen for a few hours triggers the hang.

I've got a bunch of newer video cards, but our current video drivers
don't support them, and end up using genfb with a "default" mode-line
that makes everything look wrong.  And I've already cannabilized the
old machine (which had a now non-functional GeForce 1050 Ti - maybe
it was a 1080 but I can't find any marking) so I can't go back.

At this point, I am stuck and don't know how to proceed.  I'm willing
to buy one more video card (but only one!) if I have a high likelihood
of it working.  But if there's something else going on which is likely
to be fatal no matter what video card I choose I'd rather not spend
more cash.  If you do recommend another card, please be very explicit
in identifying the make and model and any other relevant attributes
(how much graphics memory, for example).

All reasonable suggestions will be appreciated.  If there are specific
debug commands to try, please let me know.  (But also know that I don't
know much about the video subsystem - this is way beyond my usual level
of knowledge.)


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