Steppers stuttering

I have already modified my bios and reset the default settings several times.
I have tried everything concerning "Period Base", "Servo Period" nothing works.
about latency test, I have the warning also on my first PC which works very well, but I never managed to make the warning message disappear the moment LNC starts up.
On the other hand I never changed the RTAI kernel, so I have no idea how to do it.

I do my installations with the .ISO of debian 10 and I upgrade my LNC 2.8 version to 2.9 with buster.

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I installed the RTAI, but it is only in version 2.8 and I need version 2.9 for switchking. If I install version 2.9 the kernel is rtpreempt ... it does not work ...

Do you have a solution to install a version 2.9 with a RTAI kernel ?

Thanks

Indeed my PC is very stable with the RTAI kernel : test latency : 8500 jitts .
Before buying a new PC, I can also use version 2.8 since it takes into account the xyzac-trt configuration. 
But how does it work when I want to switch from TCP (M429) 5 continuous axes to (M430) 5 independent axes ?
Is it necessary to make several programs? Is it necessary to have two configurations?

Thanks

Hello , Thanks , tommylight found me a 2.9 version under linux mint 21 that works great on my PC with a relatively stable rtpreempt kernel .
My PC was not working at all with Debian and kernel 4.19 ... .

I invite everyone to switch to this version, in addition Linux mint is much more flexible and more modern than Debian 10.

The Mint 21 version is a beta version, but for having tested it in all the directions, I did not succeed in crashing it.

Thanks again to all the team for your help and assistance