> On 24 Nov 2016, at 15:47, Hubert Kario <hka...@redhat.com> wrote: > > On Wednesday, 23 November 2016 10:50:37 CET Yoav Nir wrote: >> On 23 Nov 2016, at 10:30, Nikos Mavrogiannopoulos <n...@redhat.com> wrote: >>> On Wed, 2016-11-23 at 10:05 +0200, Yoav Nir wrote: >>>> Hi, Nikos >>>> >>>> On 23 Nov 2016, at 9:06, Nikos Mavrogiannopoulos <n...@redhat.com> >>> That to my understanding is a way to reduce >>> latency in contrast to cpu costs. An increase to packet size targets >>> bandwidth rather than latency (speed). >> >> Sure, but running ‘openssl speed’ on either aes-128-cbc or hmac or sha256 >> (there’s no test for AES-GCM or ChaCha-poly) you get smallish differences >> in terms of kilobytes per second between 1024-byte buffers and 8192-byte >> buffers. And the difference going to be even smaller going to 16KB buffers, >> let alone 64KB buffers. > > this is not valid comparison. openssl speed doesn't use the hardware > accelerated codepath > > you need to use `openssl speed -evp aes-128-gcm` to see it (and yes, > aes-gcm and chacha20-poly1305 is supported then) > > What I see is nearly a 1GB/s throughput increase between 1024 and 8192 byte > blocks for AES-GCM: > > type 16 bytes 64 bytes 256 bytes 1024 bytes 8192 bytes > aes-128-gcm 614979.91k 1388369.31k 2702645.76k 3997320.76k 4932512.79k > > While indeed, for chacha20 there's little to no difference at the high end: > type 16 bytes 64 bytes 256 bytes 1024 bytes 8192 bytes > 16384 bytes > chacha20-poly1305 242518.50k 514356.72k 1035220.57k 1868933.46k > 1993609.50k 1997438.98k > > (aes-128-gcm performance from openssl-1.0.2j-1.fc24.x86_64, chacha20-poly1305 > from openssl master, both on > Intel(R) Core(TM) i7-6600U CPU @ 2.60GHz)
Cool. So you got a 23% improvement, and I got an 18% improvement for AES-GCM. I still claim (but cannot prove without modifying openssl code (maybe I’ll do that over the weekend) that the jump from 16KB to 64KB will be far, far less pronounced. Yoav _______________________________________________ TLS mailing list TLS@ietf.org https://www.ietf.org/mailman/listinfo/tls
