realtime data inserts

I have realtime data flowing at a rate of 500, 512 byte packets per second.
I want to log the info in a database table with two other columns, one for a
timestamp and one for a name of the packet.  The max rate I can achieve is
350 inserts per second on a sun blade 2000.  The inserts are grouped in a
transaction and I commit every 1200 records.  I am storing the binary data
in a bytea.  I am using the libpq conversion function.  Not sure if that is
slowing me down.  But I think it is the insert not the conversion.

Any thoughts on how to achive this goal?