It always seems to use 2 threads (200% CPU) ?
Do you have a main thread and a file reading thread ?
If I use -n 2 I get 300% CPU. I assume you use N+1 threads.
% PEAT paired -n 1 -1 R1.fq -2 R2.fq > /dev/null
% top
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
43455 tseemann 20 0 207196 143740 740 R 200.0 0.0 0:11.71 PEAT
It always seems to use 2 threads (200% CPU) ? Do you have a main thread and a file reading thread ? If I use -n 2 I get 300% CPU. I assume you use N+1 threads.