sizing the F5 appliance

I will quote from K15831: How the BIG-IP VE system enforces the licensed throughput rate

"The BIG-IP VE product license determines the maximum allowed throughput rate. When calculating throughput, the BIG-IP VE system accounts for packets ingressing and egressing the system separately. Additionally, the licensed throughput rate for ingress and egress is enforced separately. For example, if you have a 200 Mbps license, ingress into the Traffic Management Microkernel (TMM) has a limit of 200 Mbps and egress from TMM also has a limit of 200 Mbps."

However, I think the utilization of the NIC is not a quality indicator for sizing your BIG-IP appliance.

Or it shouldn't be the only parameter for sizing, take into account also connections per second and SSL TPS. Furthermore throughput and connections per second are important metrics, but they are not the only things that should be considered when sizing BIG-IP. Memory and CPU are just as important if not more important than some of the datasheet numbers. Plan for growth too.

The virtual editions datasheets will give you general performance numbers. You should refer to the datasheets as you make general sizing determinations. In most cases, these are the maximum capabilities at which either CPU or memory is completely consumed. This means determining CPU and memory requirements are extremely important in determining the appliance or virtual edition that is purchase for a solution. For, example, the amount of memory not only determines how many modules can run on a BIG-IP, but also how many concurrent connections can be maintained, as each current connection uses a finite amount of memory. CPU can be a limiting factor, HTTP compression consumers CPU, if not performed in hardware, SSL can consume CPU depending on the key size, cipher and whether the cipher is supported by hardware and for BIG-IP Virtual Editions this is always the case.

And last recommendation from: K44935357: Sizing for BIG-IP platform

"Contact your usual F5 reseller, F5 Sales, or one of F5's many Partners.

Sizing is done by Sales."