Calculation of AES encryption per second How fast in terms of the number  AES encryption/sec, would an Internet encryptor need to be if the plain text rate is 10gb/sec?
Let us assume a few things:


10 gb/sec means Gb/s, the number of gigabits per second;
we use network notation for Gb/s, which means that 1 Gb consists of 1,000,000,000 bits;
we'll use the minimum of AES blocks to encrypt - this is true for most single pass modes of encryption such as CBC and CTR;
we only use the AES primitive for confidentiality, not message integrity or authenticity (this restriction is lifted in the second part of the answer).


In that case 10 Gb/s is 1.250 GB/s. And as AES encrypts 16 bytes per block, this comes down to 78,125,000 operations per second (ops/s). Depending on the protocol and mode a few operations may be required at the start or end but those are insignificant to the ~78M ops/s.



If AES is also used for message authentication, for instance using AES-CMAC then you should double the amount of ops required.

Authenticated encryption modes based (solely) on AES such as CCM mode and EAX mode are "double pass", which means that two AES block encrypts are required for each block of input.

AES-GCM uses 128 bit modular multiplication during GMAC calculation. It is likely faster than these double pass modes, especially on newer processors with instructions to accelerate the multiplication required for GCM.