Re: Celeron J3160 with enabled Turbo mode stays at 480MHz(lowestsetting) forever and can not lower frequency without Tuebo mode

From: Benjamin Kaduk <kaduk_at_mit.edu>
Date: Wed, 5 Sep 2018 20:15:36 -0500
On Thu, Sep 06, 2018 at 03:02:29AM +0300, Lev Serebryakov wrote:
> Hello Benjamin,
> 
> Thursday, September 6, 2018, 1:32:46 AM, you wrote:
> 
> >> > I don't think you need something accurate.
> >>  Ok, here is results. I'm working in single-user mode.
> >> 
> >>  TL;DR "Turbo" mode make "openssl" much slower (x3.5)!
> >> 
> >>  I can not properly interpret this result.
> 
> > You need to say more about what openssl is doing (i.e., how it was
> > configured, what architecture it's on, etc.).  In particular, there
> > was for a time an AVX2 implementation for some primitives, that ended up
> > being a net loss, since heavy use of those instructions would cause
> > overheating and throttling.  OpenSSL has a lot of custom assembly for these
> > common primitves, with some logic to select among them both at
> > configuration time and at runtime, so results such as this may or may not
> > be widely transferrable.
> 
>  It is system (very fresh ALPHA4) openssl, built with default settings.
>  Simple single run with one thread, without AES-NI:
> 
>  openssl speed aes-256-cbc
> 
>  It is as simple as that.

Okay, "system openssl" and the FreeBSD version is enough to nail down the
code and configuration, and I see the processor type is in the subject
line.  I guess posting the CPU features bits from dmesg might save whoever
tries to track down the codepaths being used some time (unless that was
posted already and I missed it?).

-Ben
Received on Wed Sep 05 2018 - 23:20:51 UTC

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