All Cores in use, but CPU only 20% ussage

[gaukler2]

Hello

I use the tool with all cores, but only 20% CPU ussage.
Is threading really working ?
Key's are around 6500/s

Settings:
brute force bitcoin offline mode
sequential attack
Number of available cores: 8

I have 31GB of Memory and 12GB are used if i run the program.

Regards