As you may know, recent Intel processors have an extension to the x86 instruction set called Advanced Encryption Standard Instruction Set (AES-NI).

AES-NI is basically hardware support for AES based encryption and because I had a chance to run some benchmarks on differing systems I was curious what the impact of AES-NI would be.

I used TrueCrypt for running the benchmarks because this is a real life application and it had support for AES-NI.

I first ran the benchmark on a laptop with an Intel Core2 DUO (P9700 2,80 GHz):



The next system was an Intel Core i7 Q740 (Quad Core with Hyperthreading, so 8 in total) machine.



This is a real fast machine, and the Processor score confirms this:


So I was expecting a huge performance increase in the benchmarks but it’s only slightly faster:


The reason is that unlike most other i7 CPU’s the Quadcore (mobile) CPU’s do not have AES-NI support.

The big surprise was the benchmark on a machine that was in theory slower but did have AES-NI support. It had an  i7-640M CPU (Dual Core with HyperThreading):


That’s an impressive difference (around 5 times faster on AES)!

So my conclusion is that if you use Encryption software a lot (eg if you use software based Drive Encryption) an AES-NI enabled CPU is preferred.

Intel publishes a list of AES-NI enabled CPU’s here (link updated 03-01-2013).

Update 03-01-2013: Intel lists that certain processors can support AES New Instructions with a Processor Configuration update, in particular, i7-2630QM/i7-2635QM, i7-2670QM/i7-2675QM, i5-2430M/i5-2435M, i5-2410M/i5-2415M.

I’ve also ran the Benchmark on my new laptop with an Intel 2960XM which comes to a nice 3,2 GB/s for AES: