zfs discuss - Nov 2009 - High load when ''zfs send'' to the file

Hello,
when I run ''zfs send'' into the file, system (Ultra Sparc 45)
had this load:
# zfs send -R backup/zones at moving_09112009 > 
/tank/archive_snapshots/exa_all_zones_09112009.snap

Total: 107 processes, 951 lwps, load averages: 54.95, 59.46, 50.25

Is it normal?
Regards,

Jan Hlodan