Error while Running Linuxcnc

Well, one thing I want to understand i.e latency spike is solely due to computer hardware failure and not due to communication failure with mesa card, am I correct?

Well, I run sensor in terminal and output is in below:

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raycnc1@debian:~/Desktop$ sensors
coretemp-isa-0000
Adapter: ISA adapter
Package id 0:  +56.0°C  (high = +84.0°C, crit = +100.0°C)
Core 0:        +56.0°C  (high = +84.0°C, crit = +100.0°C)
Core 1:        +54.0°C  (high = +84.0°C, crit = +100.0°C)

acpitz-acpi-0
Adapter: ACPI interface
temp1:        +16.8°C  (crit = +20.8°C)
temp2:        +27.8°C  (crit = +119.0°C)
temp3:        +29.8°C  (crit = +119.0°C)

radeon-pci-0100
Adapter: PCI adapter
temp1:        +60.5°C  (crit = +120.0°C, hyst = +90.0°C)

raycnc1@debian:~/Desktop$
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Now the max jotter is 7000ns (servo thread) and 11880ns(base thread). If any thing abnormal in above data, please reply.

I am waiting for the spike to happen again and check sensor data again.
 

Graphics card is added, not built-in. Without graphics card, max jitter comes in the range of 50,000ns~80,000ns.

And this morning I faced new error situation. Screen shot attached. It is reading error as message says. What exactly causes it? Machine inputs and outputs stops working with this error.
.
 

Well  today I measured temperature readings with Infrared thermometer as follows:

Ambient 32 degree C.
7i92 on FPGA chip(black/square shape)= 45~47 degree C.
7i76, 7i84= 39~42 degree C.
 Stepper drivers=40~43 degree C.
SMPS=39~42 degree C.

Note-1)  I had intentionally kept the cooling fan of the panels off to check the maximum temperature rise pattern.
Note-2) ambient temp easily goes upto 45 Degree C in summer (Now Autum here) and considering its application i.e oxyfuel cutting for intended 12~16 hour per day in Industrial environment, ambient will reach upto 50 degreeC.

Now, is such temperature are suitable for Mesa and computer hardwares? What shall be the maximum allowable limit as I am planning to install temperature switch in Panel.
 

Those temperatures are all fine.

I would suspect failing PC hardware with the 49 ms latency spike

Can you try without the graphic card installed?

Today I removed the graphics card and ran the machine.

Latency data in attached screen shot. Latency test and Linuxcnc run together.

I increased the servo period.

but "error finishing read" continues.

What to do?

Have you disabled all power saving in the BIOS? (C states >C1, any turbo mode etc)

What actual PC hardware are you using?

It may be that it is not suited to real time

(a 49 ms real time delay is fatal for any LinuxCNC installation running actual motion hardware)

Bios power saving options already disabled. It is a dual core processor, isolcpus=1 set, latency max jitter comes 50,000ns to 85,000ns(as the graphics card already removed), ping test data already given in this topic earlier. What else to check? 

One more question: I have a Raspberry pi4, 2GB ram in stock. Any better result expected with that?