Refresh large delays (axis)

I have several machines running linuxcnc. Configurations are quite different, linuxcnc versions are also different and hardware (PC and Mesa cards also different to suit each machine). Machines are lathes, a water jet and a plasma cutter.
Common to all machines are hand made components (but different between them), panel with encoder, buttons, ...

In most - or all - it is frequent to have large delays (5 - 10 seconds) when refreshing or loading gcode files in axis. In my case files are never large - maybe 300 lines of code. The delay is not consistent, for example if I reload the same file 10 times it can happen 2 or 8.

No problem during code execution.

I have searched the forum and I could not find anyone complaining about this, so I do not know if this is because my configuration (that I do not believe because they are different) or another thing that I am doing consistently wrong in all machines.

The delay seams graphically only, does not trigger any error, but freezes axis completely.

Any comment would be much appreciated.
Thank you

i'd go along the lines of your motherboards or graphics cards are marginal . i dont have the problems you suggest .
i dont use high end mb's but i do make sure they have at least 2g memory and 512 graphics minium

over the last few years the requirements have grown considerably for linuxcnc .
however you do not mention which version of linuxcnc , not the approprate age or spec of the motherboards
however i feel a look at any external graphics might help . onboard graphics do tend to be low grade .
although a generalisation over all .

All motherboards are very recent. Bought on purpose for the work as I need to provide warranty on all parts that I install. I also install only SSDs. This happens with 2.6 to 2.7 to master versions (I have machines will all those versions).

Most systems have 4Gb memory, both most (or all) are using the internal graphics card - that are nowadays quite fast.
I will try to install a external graphics card on one of the machines to see if I still have the issue, or try to provide more memory to the on board graphics card.

Latest was a quadcore processor with a very good latency and general speed on all applications, so it is really strange the delays.

I will post again if something is found, but I would like to hear if someone else have the issue.

Are the machines software stepping machines with very fast base-threads? At some point if the base-thread gets too fast it can consume too much of the computers resources, slowing things to a crawl. Otherwise it might be an OpenGL hiccup, that a different graphics possessor or drivers might help.

All the machines are hardware (Mesa) based. The refresh or load is always done with the machine in idle mode, so no motion to consume resources.

In the meanwhile after cncbasher reply, I placed 512Mb in shared memory on a machine that is now with me (with onboard graphics - before it was in AUTO mode the shared memory) and it seams for today that it was ok.
Probably to soon to mark as solved, but it looks promising.

Like I told, since Friday I changed the onboard video card memory and it looks ok, maybe a few more days of testing will be conclusive. But I also like the idea of a issue with the SSD, at least it would be consistent with the issue as it occurs only in loading or refreshing a code.