Hi Geoff!
I too have 3590 FC drives, two of them.
Each drive is able to deliver about 30 Mbytes/sec throughput max. A FC link
can deliver up to 100 Mbytes/sec throughput. So, addressing 3 drives through
a switch should not degrade performance. However, here in the Netherlands,
fibrechannel switches are VERY expensive, so for us was cheaper to connect
both drives to the AIX host directly, using two FC adapters.
Kindest regards,
Eric van Loon
KLM Royal Dutch Airlines