cant run latency histogram

That reminds me, OP listed Radeon R7 350 4GB at amazon link in first post.

Might be worth checking if installing nonfree firmware fixes it
what does
sudo dmesg | grep gpu
report?

glxgears runs fine from a terminal. i was using a couple Nvida cards early on, but they had other issuse with scrambling the screen. so I was told an AMD card is prefered for Linuxcnc anyway, because the proper drivers are baked in. Thats why i got that amazon one.
I'll try and download the ISO again and use a different USB. but i cant for the life of me find anything about secure boot in my bios.

rubes@x3cnc:~$ sudo dmesg | grep gpu
[sudo] password for rubes:
[ 3.922158] [drm] GART: num cpu pages 524288, num gpu pages 524288
[ 3.948192] radeon 0000:03:00.0: fence driver on ring 0 use gpu addr 0x0000000100000c00
[ 3.948194] radeon 0000:03:00.0: fence driver on ring 1 use gpu addr 0x0000000100000c04
[ 3.948196] radeon 0000:03:00.0: fence driver on ring 2 use gpu addr 0x0000000100000c08
[ 3.948197] radeon 0000:03:00.0: fence driver on ring 3 use gpu addr 0x0000000100000c0c
[ 3.948198] radeon 0000:03:00.0: fence driver on ring 4 use gpu addr 0x0000000100000c10
[ 3.948609] radeon 0000:03:00.0: fence driver on ring 5 use gpu addr 0x0000000000075a18
[ 3.968652] radeon 0000:03:00.0: fence driver on ring 6 use gpu addr 0x0000000100000c18
[ 3.968654] radeon 0000:03:00.0: fence driver on ring 7 use gpu addr 0x0000000100000c1c
[ 11.149261] amdgpu: Virtual CRAT table created for CPU
[ 11.149286] amdgpu: Topology: Add CPU node
rubes@x3cnc:~$

I wouldnt begin to know how to decipher that.

oh, that explains it i guess. And no, MOBO does not have integrated graphics. guess im buying another graphics card

It’s the same situation for me; I solved it by switching to an AMD "display-only" card.

the CPU is a xenon 5650

tommylight wrote:

AMD graphic cards do not work with new RT kernels, 4.19 is the last one that worked.
Does the CPU have an integrated graphic?
Intel works fine with RT kernel, NVIDIA works but causes issues so is unusable, AMD goes to black screen, al this with 6.13 RT kernel.
Had no time to test the 7.nn kernels yet.
 

There is some bug in newer amdgpu driver, but works.
My Ryzens work with all Debian13 RT kernels (computer I write from is Ryzen 5500U, kernel 6.12.95+deb13-rt-amd64).
My AMD A10-7800 work with 6.12.63+deb13-rt-amd64 RT kernel.
With newer than 6.12.63+deb13-rt-amd64 works too, but only with low or medium resolution, enough for Axis or Gmoccapy.
The solution for blank screen is boot with nomodeset kernel parameter (gpu runs but without hardware acceleration) and change GRUB's and system's screen resolution to low, restart and test higher resolutions.