USB hub error messages in UNIX. Slow performance

MMacBook Pro, i7, 2.2ghz, El Capitan OS

system slow, went into UNIX to run fsck -fly, but difficult as continueing listing of error msg, USB error messges.

ran DiskAid, said system fine, reinstalled El Capitan, but error msg persist. No USB plugged in.

how can I delete, or stop these msg, so system will run normal Again.

thanks