[nsp] Packets per second?

[cisco-nsp@thedogsbollocks.co.uk]

Hi all,
 I was just comparing various cisco 7xxx routers and associated processors/vips
so went thro the data sheets noting down architecture and the reported packets
per second and backplane info.

I'm just wondering what they benchmarked this on! For example I have a 7206/225
with 18000pps averaging 40% CPU and spiking each minute (BGP scanner
etc). According to the docs the NPE225 can do 225000pps... hmm, I'm doubting
this!

Am curious to know if anyone has played with these numbers at all to try and
benchmark one router to another and if there was anything interesting found.. 

eg cisco's figures are too high by a factor of X

eg the NPE225 which rates the same PPS as an RSP2 is actually 10 times more
efficient because of its _______.

you see what i'm getting at here? (no references to distributed architecture
white paper please!)

i have a feel for how these routers perform but i'm trying to quantify it - and
not doing so well! 

I'm specifically interested in the performance of various VIPs in a 7500 chassis
which again altho I know theyre N times better than the 7200 from experience,
precisely what is the multiplying factor and whats the reason? A couple of
VIP2-50s rated at 90000PPS can easily keep up with an NPE300 rated at 300000PPS,
weird!

Cisco's vagueness, departure from measured figures and inconsistency in data
sheet reporting has me beated! :)

TIA

Steve