These machines can print slowly for a varity of reasons. First and foremost is using the incorrect driver. The correct driver can be downloaded here:
http://www.usa.canon.com/opd/controller?act=OPDSoftwareAct&fcategoryid=2275&modelid=6349
Also slow printing can be a symtom of a hard drive about to fail (e602 codes).
Fastest printing speeds can be achieved using the following basic assumptions:
1) The copier is printing thru a standard cat5 cable; not thru the parallel port.
2) The network the copier is on is healthy and operating normally.
3) The network settings on the copier are configured correctly.
I am a Canon trained authorized tech on these machines and have been working in the field on the ImageRunner 3300 series since their release. I'm not sure if a ram upgrade is available but I haven't installed one in the six plus years of servicing this machine to fix a slow print problem.