"On our production frontend machines, SSL/TLS accounts for less than 1% of the CPU load" according to Google back in January 2010 [1]. This was about the same time as Intel introduced AES instructions, but the post suggests that this wasn't a big factor in their conclusion that TLS simply isn't computationally expensive.

[1] https://www.imperialviolet.org/2010/06/25/overclocking-ssl.h...