2 or 4 kernel CPU

What is better for linuxcnc. I've bought a 4kernel Celeron SoC Board and it seems quite good. Latencytest in the range of 7000. I have tried a rather old S775 dualkernel Board who is at 20.000 although the frequency is 1.5 times of the 4kernel, but the ram chips are 2 Generations back. But I don't know if LC uses all kernels or is it better I use a 2kernel Board with much higher speed.

But I don't know if LC uses all kernels or is it better I use a 2kernel Board with much higher speed.

There is no advantage whatsoever in using multi-core processors, the best latency is obtained when isolating all but one core.
That said, use whatever suits best, it is quite possible to have a 4 core machine that runs better than a dual core.

The speed of the RAM and the processor, beyond a certain point, matters little too.
The most basic computer is capable of outputting instructions far faster than any machine can execute them.

An Atom mini ITX MB with a 1.6GHz dual core processor (with one core isolated) and 2MB of RAM is pretty much the bench mark for low latency, low cost machine.
The good ones are between 5K and 10K max jitter on base thread, which is more than adequate for software stepping.

regards

My Board is the follower of the Atom, instead 1,8GHz Atom it uses a 4kernel 2GHz Celeron Prozessor, but a similiar Board with a 2Kernel but 2.4GHz Celeron is available as well. Because I have to retrofit 2 Machines I want know, which one is better, although 7000 latency should be good enough.