. Bandwidth Threshold on Cisco 3750

Does anyone know if at layer 3 an interface has a limit ?

I have been told that even thought our WS-C3750V2-48PS-S  switch has 1GB ports that we can expect much lower bandwidth throughput on the ports if we are using layer 3 on those ports

I'm trying to find some documentation that explains this but nothing clear is coming up

All switches have a limit in layer 2 forwarding, usually expressed in Gbps or Mbps. It's sometimes called the backplane bandwidth.

Layer 3 switches also have a limit in routing, expressed in (IP) packets per second: Mpps.

For a routing device, routing a 16 byte ICMP 'ping' packet is the same effort as routing a 1450 byte TCP packet carrying HTTP. If you multiply your average packet size with this Mpps value, you get an average Mbps value that indicates your L3 performance.

Not sure about the 3750 (and it'll depend on the exact model), but from memory even the 3550-48 had the horsepower to do layer3 at 1Gbps with 800byte packets; and compared to that, even a first generation WS-C3750X-24T-L  is a monster.