cant run latency histogram

P1 can be used for step/dir with the right firmware (that puts stepgens on those pins)
Mesa Ethernet cards don't use the base thread at all.

latency-histogram --base 100000

Means the base thread _period_ is 100000 ns = 100 us, 1/100us = 10 Khz

doh!!!! thanx for the reminder in how to do basic frequency conversions...LOL

Google ai's answer is quite incorrect. I don't see what cpu you got, but with the motherboard you listed, I think any CPU it would be compatible with would have many times more capacity than what LinuxCNC could possibly use.

There are a couple different things that could cause your problem:
1. Possible data error during iso file download and install. Download a second copy and try that or maybe install 7zip which is one program I think of right now which makes it convenient to check sum files in Windows.
2. USB memory device error - try a different one.
3. Motherboard/hardware incompatibility. What you got certainly is fast and powerful enough for LinuxCNC but sometimes odd incompatibilities pop up between hardware/firmware/OS.

Open a terminal and type:
glxgears
if it crashes = change the graphic cars ... that usually can not be done as they are inside the CPU, but if you have a spare PCI-E slot, find an old one and give it a try.
If it runs fine, still i would insist on disabling secure boot and/or trying another ISO/USB.

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.