[c-nsp] PPS rate between ports on a 6500?

[FXCM - Brandon Palmer]

I've searched pretty hard and passed this through a few CCIEs, all with
no luck:

I have a 6506 w/ sup2 (256m) and a 6148 blade.  For DDOS testing,  I've
connected a workstation (gig, full dup) to one of the ports that is
generating syn-flood at ~ 115kpps (as per sh int).  The port for the
target (gig, full dup as well) IP address (again,  as per sh int), 
however,  is only getting 50kpps.  During the test runs,  the cpu on the
6500 is ~ 15%.  Is this a limitation of the blade?  Am I missing
something obvious here?

Thanks folks.
- Brandon