we have an 2240-4 with a 10G Dual Mezzanin card installed. 8.2.3 7-Mode
Usually the system is just under load at night, exclusivly for 95 % snapmirror destination and 5 % CIFS backups.
Now if i disabled our normal 2x1G RJ45 VIF, and start 1 (!!!!) CIFS transfer from a fast source to the 2240 i end up having about only 50mb/s AND 100 % CPU load. If i stop the transfer, usage is back to 14% CPU.