Older FCX 648-S - troubleshooting throughput issues, + firmware upgrade questions

[chris_wilson_cx]

My office has an older Brocade FCX 648-S from which I'm trying to get more throughput.  It's configured as a layer-3 switch with several VLANs.  I've only been able to get about 150 Mbit sustained throughput from any single client connection.

So far I've double-checked port speed/duplex settings, known-good Ethernet cables, etc.  I tried disabling flow control (no effect).  I'm not really sure what else to try.  I'm fairly knowledgeable on networking in general, but am admittedly not a network engineer or a router/switch configuration expert. 

Any thoughts on how to diagnose where the problem is?  Or, am I really just dealing with a function of old hardware? 

The switch is currently running software version 7.0.01b.  I see there is an 08.0.30t version on the Ruckus site.  Should I try upgrading, and if so, is it safe to jump straight to the latest version?

Thanks,

-Chris