Do I need a better PC?

ok, sometimes when I run my Ethercat servos, they sound like they have bad bearings/run rough. Restarting linuxcnc sometimes solves it and they run buttery smooth. I've also gotten a warning unexpected realtime delay. Im guessing Its because Im running the cheapest HP pavilion desktop junk(runs off a little wall wart and has the smallest cooling fan on a 1x1" cpu heat sink. ) 
Anything I should look for when buying a proper motherboard for ethercat linuxcnc?

I don't think its a servo hardware issue. All of them sound like gravel sometimes. Or they are all smooth. I'm wondering if its something to do with the feedback loop between the servo and linuxcnc? It sounds like they are being commanded unsteady changing speeds at a somewhat high frequency. They only have UVW coming out of the motor. And encoder seems to have standard a/b v+ v- stuff going on. I don't think there's any hall sensor for the rotor.

I have had this gravel sound. Starts by sounding like tick, tick gradually transitioning to gravel and going back to tick,tick and disappear.
Repeats itself after some minutes.
It may not be what causes it for you, but in my case it was a slight difference in the DC cycle time and linuxcnc cycle time.
One is running slightly faster than the other. Both nominally 1 millisec, Combined with some latency of the linuxcnc computer
ethercat will send and receive data not from the current servo cycle, but from the previous or the next cycle.
The gravel sound would appear with the transition over this mixed period to stabilize when the cycles are so much out of phase that they always receive data from the same servo cycle phase.

You can check with halscope of the actual position for example. When the gravel sound happens you will see that
the actual position isn't a smooth line anymore as is expected. Instead you will see that it stays on the same
position for a cycle, to maybe jump double distance another. This is worthwhile checking. 
Two curves in halscope, commanded position and actual position, with and without gravel sound would be interesting to see.

interesting. Im playing with the servos now. Today im getting an error code ErC1.1 Synchronization loss on all 5 drives. and ErC2.0 SYNC signal loss on some drives sometimes. I will power cycle PC and see what happens. my 3 axis config seems ok.

my servo latency was 178,165 base was 79,029

now its around 72000 and is working without alarming my servos.

youtube.com/shorts/vI0LGnGjhmI?si=QLHawiX2xE67YjWh

youtube.com/shorts/FzLijBCwhX8?si=wHB4NtbOI7QP0iu-

Here's 2 clips, one "gravel mode" and one right after restarting linuxcnc running smooth.

can you share your full config?