Is the CPU not strong enough?

I just received my drobo FS two days ago and i’ve been spending my time filling up my 4.5 TBs of free space when i realized that it’s painfully slow at 20mb/sec
Installing the SSH client and running top i realised that the CPU is staying at 100%, where smbd (the samba daemon) is running in the low 90% range and the rest is being used by system processes

490 352 root R 11108 5.8 0 87.2 /sbin/smbd -s /mnt/DroboFS/System/samba/conf/smb.conf
44 2 root SW 0 0.0 0 6.9 [pdflush]
274 2 root SW< 0 0.0 0 4.1 [dri_scsi_req_3]
292 2 root SW< 0 0.0 0 1.2 [kjournald][/font]

Should smbd be using so many resources? would it be better to use ftp rather than SMB for less overhead? I’ve never known a system to spend so much time using samba (admittedly they were all over 1 ghz processors)

Just installed the ftp daemon and the transfer speeds jumped up to 35mb/sec (this is all using non-jumbo frames)

Any idea if it’s possible to optimize smbd?

A lot of devices have this issue from what I’ve experienced, somehow the producers try to cut costs on internal HW like CPU, even my 99 dollar Sheeva Plug (which has a fully usable Linux OS inside) has more power than most.

I’ve achieved about 35MB/sec over AFP and jumbo frames, although most of the time it’s more like 17MB/sec. For my purposes this made for a very, very lengthy migration, but I don’t need speed too often - it’s a video repository and glorified WORM for me.

EDIT: On a new unit, I’m getting 38MB/sec read and 25MB/sec write, without jumbo frames.