I found the solution sk109236 - "High CPU / process crashes / timeout due to large database / first time operations / load on the machine".
The solution to get better performance is to modify the connection buffer.
"The size of the Communication Buffer is hard-coded to 1MB-4MB depending on the version (For R77.10 and above: 4MB)."
"It is strongly suggested to set FWASYNC_MAXBUF=40000000 (or more, according to what the allocation failed on, i.e. if it failed on 40MB, then set to 80MB)"
- What does the buffer do?
- What is the limit of increasing the buffer?
- Why is 40 MB not default?