Gentoo Archives: gentoo-user

From: Mark Knecht <markknecht@×××××.com>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] Re: Check CPU for throttling
Date: Tue, 10 May 2011 18:12:19
Message-Id: BANLkTimAHxFKnJXSfrc9+BZc_OXjXM5+FQ@mail.gmail.com
In Reply to: Re: [gentoo-user] Re: Check CPU for throttling by Bill Longman
1 On Tue, May 10, 2011 at 9:38 AM, Bill Longman <bill.longman@×××××.com> wrote:
2 > On 05/10/2011 09:34 AM, James wrote:
3 >> Alan McKinnon <alan.mckinnon <at> gmail.com> writes:
4 >>
5 >>
6 >>> otherwise. Just enable ondemand, disable everything else, and et the kernel
7 >>> get on with doing what it does best:
8 >>
9 >> So this is what you are saying?
10 >>
11 >>
12 >>  [*] CPU Frequency scaling                                         │ │
13 >>   │ │    [*]   Enable CPUfreq debugging                            │ │
14 >>   │ │    <*>   CPU frequency translation statistics                │ │
15 >>   │ │    [ ]     CPU frequency translation statistics details      │ │
16 >>   │ │          Default CPUFreq governor (performance)  --->        │ │
17 >>   │ │    -*-   'performance' governor                              │ │
18 >>   │ │    < >   'powersave' governor                                │ │
19 >>   │ │    < >   'userspace' governor for userspace frequency scaling│ │
20 >>   │ │    <*>   'ondemand' cpufreq policy governor                  │ │
21 >>   │ │    < >   'conservative' cpufreq governor                     │ │
22 >>   │ │          *** CPUFreq processor drivers ***                   │ │
23 >>   │ │    < >   Processor Clocking Control interface driver         │ │
24 >>   │ │    <*>   ACPI Processor P-States driver                      │ │
25 >>   │ │    < >   AMD Opteron/Athlon64 PowerNow!                      │ │
26 >>   │ │    < >   Intel Enhanced SpeedStep (deprecated)               │ │
27 >>   │ │    < >   Intel Pentium 4 clock modulation
28 >>
29 >>
30 >
31 > Yes but no. Yes, those are the correct choices, but the default governor
32 > should be ondemand.
33
34 Or in the case of the OP who is brave enough (or silly enough?) to
35 risk the long term reliability of his CPU running it with no fan,
36 possibly choose powersave with a specific low clock rate as the
37 default and then switch to either ondemand or conservative manually
38 when he needs more performance. In a machine such as he's playing with
39 I wonder if he really wants ondemand (jumps to max and then slows down
40 over time) vs conservative which more slowly ramps up the clock rate
41 if the job at hand takes more time.
42
43 It's all a trade off of performance vs power & heat.
44
45 On my 12 thread server I've played with these two and frankly don't
46 see a lot of difference doing any large job. They are both a bot
47 slower than running performance, but I save a lot of power (and over
48 time money) using them so I'm happy.
49
50 - Mark

Replies

Subject Author
Re: [gentoo-user] Re: Check CPU for throttling Mick <michaelkintzios@×××××.com>