Re: AES-NI: slower than aes-generic?

[Stephan Mueller <smueller@chronox.de>]

Am Donnerstag, 26. Mai 2016, 13:25:02 schrieb Jeffrey Walton:

Hi Jeffrey,

> > What I am wondering is that when encrypting 256 16 byte blocks, I get a
> > speed of about 170 MB/s with the AES-NI driver. When using the
> > aes-generic or aes- asm, I get up to 180 MB/s with all else being equal.
> > Note, that figure includes a copy_to_user of the generated data.
> > 
> > ...
> 
> Something sounds amiss.
> 
> AES-NI should be on the order of magnitude faster than a generic
> implementation. Can you verify AES-NI is actually using AES-NI, and
> aes-generic is a software implementation?

I am pretty sure I am using the right implementations as I checked the 
refcount in /proc/crypto.
> 
> Here are some OpenSSL numbers. EVP uses AES-NI when available.
> Omitting -evp means its software only (no hardware acceleration, like
> AES-NI).

I understand that AES-NI should be faster. That is what I am wondering about.

However, the key difference to a standard speed test is that I set up a new 
key schedule quite frequently. And I would suspect that something is going on 
here...

Ciao
Stephan