LinuxCNC installation + 7I96S

I have installed: 8168 driver

When I enter this in the terminal:
cpufreq-info | grep "current policy"

I get this:
current policy: frequency should be within 800 MHz and 3.20 GHz.

I cannot change to a constant 3.20 GHz.

The only reason I asked about the CPU frequency is that the tmax values are in CPU clocks
(on X86 hardware). Knowing the CPU frequency allows the times to be calculated.

So what is it due to?

Should I change the network card?

For this: www.amazon.es/Euqvos-Gigabit-Desktop-PCI...ef=asc_df_B09SXXYV4R ?

I have executed this in a terminal:
sudo cyclictest -l 10000 -m -p 80 -i 1000 -q -v

He has given me this:

0: 9996: 2
0: 9997: 2
0: 9998: 2
0: 9999: 2
T: 0 ( 2995) P:80 I:1000 C: 10000 Min: 2 Act: 2 Avg: 2 Max: 7

It seems that by switching to r8168, I am no longer getting the error.

I currently have 3 axes, but I will be installing 5 simultaneous axes. Is it advisable to change the network card?

Normally the DKMS 8168 driver will fix the Ethernet latency issues

If it's not sufficient, one additional step to do is to  use isolcpus
to isolate the last processor and then pin the Ethernet IRQ to that
processor.
 

Can you explain how to do it?

Now I just need to configure the INI to mm and the speeds. I'm getting errors from

hm2/hm2_7i965.0: stepgen.00.maxvel is too big for current step timings & position-scale, clipping to max possible

For isolcpus:http://wiki.linuxcnc.org/cgi-bin/wiki.pl?The_Isolcpus_Boot_Parameter_And_GRUB2

For pinning the IRQ there is a script for testing here: 

 

to run, first download the script then:

chmod +x pinirq.txt

then

sudo ./pinirq.txt [ethernet_device_name]