Depending on the platform you have take a look at the router performance pdf (http://www.cisco.com/web/partners/downl ... rmance.pdf
) and see what it is rated for, that number doesnt matter whether it is inside to outside or just between subnets on the same router, as they are all doing basically the same thing (a L2/L3 packet rewrite).
Bare in mind with the numbers in that PDF though that they are tested using pretty small packet sizes.
And your query regarding the L3 switch, yes you will be able to a LOT faster transfers using a L3 switch as the gateway between the two different subnets.
Thank you very much. I have reviewed that document you linked. I have a 1921 that we are talking about here so it is either the same as or extremely close to the 1941. 1921 isn't listed so I have to assume for now that the router can forward 299,000pps. Doesn't cisco test at 64k packet sizes?
At any rate I may still ask to borrow a friends 3750e gig switch to do some testing and learning on. I sincerely appreciate your confirmation on the l3 switching question I have. I also appreciate you clearing up the limit of what the router can address is on both interfaces combined, one single interface, or a combination as a global max in performance. I believe the only way at this point to keep cpu usage below an acceptable (where I feel safe) 75% is to cap the interface speed at 100 or as you have confirmed use a l3 switch.