Master/Media server:  Solaris 8 - NB DataCenter 4.5 MP3
Tape drive:  STK9940B 
Disk:  EMC

I am running a backup on some file systems on EMC storage, total size is
about 500GB, on the master server.  If I used one stream and one tape drive,
I get a transfer rate of about 30 MB/sec and it takes about 5 hours.  When I
break it down to 4 streams and use 4 tape drives, I get 4 jobs with a rate
of about 7MB/sec and still take 5 hours.  It looks like the transfer rate is
divided by 4.  How can I get all 4 jobs to go faster and where can I look to
see why?

Thanks,
Ken