[c-nsp] GRE router recommendations

[Simon Lockhart]

Is anyone aware of any documents detailing the GRE performance of different
Cisco devices?

I'm in the process of designing a network which will need to tunnel back to 
the core, for which I'm intending to use GRE.

At the sites where I need to tunnel from are currently 3550 switches (and
a few 3750's). What sort of GRE performance should I see from those?

Assuming I use something other than the 3550 for GRE, what device would give
me GRE at 100Mbps? 300Mbps? 500Mbps? 1Gbps? 5Gbps?

Many thanks,

Simon