Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Thu, 8 Sep 2016 12:03:16 +0800
From: Lei Zhang <>
Subject: Re: Intel KNL test machine

2016-09-08 5:14 GMT+08:00 Lukas Odzioba <>:
> 2016-09-07 15:25 GMT+02:00 Solar Designer <>:
>> Yes, thanks.  Lukas already ran some benchmarks on a similar device, but
>> I think he never published those, in part because the descrypt ones were
>> for AVX2 rather than AVX-512.
> I think I can find some spare time this weekend to try to fix code,
> rerun my tests
> and post results, unless Lei wants to do this - which I don't mind :)
> Have in mind that AVX512 there is a different set of instructions from
> those on KNC,
> so it's better to use some recent compiler. Also Linux kernel must
> support avx512,
> which you can check via $ cat /proc/cpuinfo | grep -i avx512
> There should be avx512f, avx512pf, avx512cd, avx512er extensions.

The memory model also changed. In KNC native mode, all memory usage
happens in the co-processor's 8GB high-bandwidth memory (I forgot the
exact name...). But KNL is a host CPU; it supports normal DDR and in
the meantime also has its own high-bandwidth memory, which is called
MCDRAM [1].  DDR is the default; special functions are needed to
utilize MCDRAM.

I don't know how much impact memory throughput has on John's
performance. Perhaps John needs to explicitly support KNL's memory
model to fully extract performance from it.



Powered by blists - more mailing lists

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.