Impact when moving from 2048 to 4096 bit RSA keys

We did just close the case and it pretty much boils down to this:

Performance should be impacted by (up to) 17x comparing 1024 and 4096 bit keys, factor between 1024 and 2048 is 4x. See K13067: Performance impact of transitioning to 2048-bit SSL key sizes to this in detail.

Regarding licensing, there is quite some explanation available in K6475: Overview of SSL TPS licensing limits.

A few ressources outside were provided regrading this topic:

• Yubico Blog - The Big Debate, 2048 vs. 4096, Yubico’s Position
• Random Notes - HTTPS Performance, 2048-bit vs 4096-bit
• CertSimple - So you're making an RSA key for an HTTPS certificate. What key size do you use?

For actual measurements F5 refers to professional services.