Hi
I know Juniper has a table for each high-end srx that explains how
large performance you get for each card combination. Check presentations on partner's
site for the latest version of it.
But definitely, you will not get 30Gbps with 1 SPC. The trick is that SPCs nad NPCs are
doing different jobs in SRX3000:
SPCs - do session processing and services such as IDP, IPSec, etc
NPCs - do session lookups and some hw feautes like screens and CoS
and you need both types of cards in your chassis. Generally, 1 SPC is maximum 10G
firewall, so for 30G you will need at least 3, BUT!! one of the SPCs is doing the
Central point functionality so it will be 4 SPCs, and also 3 NPCs to get 30G of firewall.
This is the maximum performance (large packet and lab environment), and real one
will be, of course, smaller.
I hope this at least explains the concept.