Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.sys.mac.system > #58619

Re: 10.9 - disabling memory compression

From Lewis <g.kreme@gmail.com.dontsendmecopies>
Newsgroups comp.sys.mac.system
Subject Re: 10.9 - disabling memory compression
Date 2014-04-18 05:55 +0000
Organization Miskatonic U
Message-ID <slrnll1fhr.1v7.g.kreme@amelia.local> (permalink)
References (1 earlier) <slrnlkt1il.m1e.g.kreme@amelia.local> <ivGdnYspFZvkbdPOnZ2dnUVZ_vadnZ2d@giganews.com> <slrnlku6kh.1b7j.g.kreme@amelia.local> <lZednfcNMN_dtc3OnZ2dnUVZ_qCdnZ2d@giganews.com> <braoc8Ft7gU1@mid.individual.net>

Show all headers | View raw

In message <braoc8Ft7gU1@mid.individual.net> 
  android <here@there.was> wrote:
> In article <lZednfcNMN_dtc3OnZ2dnUVZ_qCdnZ2d@giganews.com>,
>  Alan Browne <alan.browne@FreelunchVideotron.ca> wrote:

>> And yes, there is a gain by turning it off.  Compression, even as cpu 
>> efficient as the technique used, does use cpu cycles.

> Have you noticed it?

No, he hasn't. He's much like the audiodweeb, "See, now that I switched
over to the $100/ft speaker wire, the sound is so much better!"

*THAT* is ad hominem, btw.

> Do you know what kind of compression it is? Is it 
> merely defraging the ram or is it reusing file fragments?

John Siracusa:
Like the HFS+ compression feature introduced in Snow Leopard, compressed
memory trades relatively abundant CPU cycles for decreased disk I/O. The
compression and decompression process is extremely fast, using the WKdm
compression algorithm, and it will run in parallel, taking advantage of
multiple CPU cores.

Intuitively, a multi-core CPU grinding away compressing data in RAM does
not seem like a winning strategy to save energy. But our intuition is
often wrong when it comes to real-world energy use on modern hardware.
Remember, it’s a race to sleep! Avoiding shuttling data between RAM and
that hundreds-of-times-slower-than-RAM SSD is a big win as long as the
compression task can be completed in a fraction of the time it would
take to access the SSD. It can be, and it is.

<http://arstechnica.com/apple/2013/10/os-x-10-9/17/>
<<END

In short, compressing memory is cheap (actually, much closer to
out-right free), and it means the system is less likely to use the swap
file. The more memory you have, the less likely you are to use the
swapfile. Disabling it means that the system goes straight to the
swapfile as soon as it wants to dump something out of RAM. Upshot,
disabling compression will almost certainly cause the machine to be much
slower under load.

tl;dr version: don't do this.

-- 
"There's sex and death and human grime in monochrome for one thin dime
and at least the trains all run on time but they don't go anywhere."

Back to comp.sys.mac.system | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-13 12:07 -0400
  Re: 10.9 - disabling memory compression billy@MIX.COM - 2014-04-13 17:57 +0000
    Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-13 15:35 -0400
  Re: 10.9 - disabling memory compression Warren Oates <warren.oates@gmail.com> - 2014-04-13 14:50 -0400
    Re: 10.9 - disabling memory compression Paul Sture <nospam@sture.ch> - 2014-04-13 21:18 +0200
      Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-13 15:55 -0400
    Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-13 15:37 -0400
      Re: 10.9 - disabling memory compression Warren Oates <warren.oates@gmail.com> - 2014-04-13 15:51 -0400
    Re: 10.9 - disabling memory compression Leonard Blaisdell <leoblaisdell@sbcglobal.net> - 2014-04-13 19:35 -0700
      Re: 10.9 - disabling memory compression Your Name <YourName@YourISP.com> - 2014-04-14 16:34 +1200
        Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-14 16:30 -0400
          Re: 10.9 - disabling memory compression Paul Sture <nospam@sture.ch> - 2014-04-20 10:53 +0200
            Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-20 09:27 -0400
      Re: 10.9 - disabling memory compression Warren Oates <warren.oates@gmail.com> - 2014-04-14 07:51 -0400
        Re: 10.9 - disabling memory compression Lewis <g.kreme@gmail.com.dontsendmecopies> - 2014-04-16 13:35 +0000
      Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-14 16:30 -0400
        Re: 10.9 - disabling memory compression JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-04-14 17:36 -0400
          Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-14 18:06 -0400
          Re: 10.9 - disabling memory compression Paul Sture <nospam@sture.ch> - 2014-04-20 09:15 +0200
        Re: 10.9 - disabling memory compression me@home.spamsucks.ca (Király) - 2014-04-15 06:01 +0000
          Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-16 16:54 -0400
        Re: 10.9 - disabling memory compression Paul Sture <nospam@sture.ch> - 2014-04-20 09:11 +0200
          Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-20 09:24 -0400
      Re: 10.9 - disabling memory compression Jolly Roger <jollyroger@pobox.com> - 2014-04-15 02:10 +0000
  Re: 10.9 - disabling memory compression Rick Jones <rick.jones2@hp.com> - 2014-04-14 23:32 +0000
    Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-14 19:58 -0400
    Re: 10.9 - disabling memory compression Paul Sture <nospam@sture.ch> - 2014-04-20 09:45 +0200
      Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-20 09:26 -0400
  Re: 10.9 - disabling memory compression Kevin McMurtrie <mcmurtrie@pixelmemory.us> - 2014-04-15 00:38 -0700
    Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-16 16:58 -0400
  Re: 10.9 - disabling memory compression Lewis <g.kreme@gmail.com.dontsendmecopies> - 2014-04-16 13:32 +0000
    Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-16 17:04 -0400
      Re: 10.9 - disabling memory compression Lewis <g.kreme@gmail.com.dontsendmecopies> - 2014-04-17 00:04 +0000
        Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-17 15:15 -0400
          Re: 10.9 - disabling memory compression android <here@there.was> - 2014-04-17 21:29 +0200
          Re: 10.9 - disabling memory compression android <here@there.was> - 2014-04-17 21:29 +0200
            Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-17 15:48 -0400
              Re: 10.9 - disabling memory compression android <here@there.was> - 2014-04-17 21:58 +0200
                Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-17 16:07 -0400
                Re: 10.9 - disabling memory compression billy@MIX.COM - 2014-04-19 16:06 +0000
                Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-19 12:37 -0400
                Re: 10.9 - disabling memory compression Lewis <g.kreme@gmail.com.dontsendmecopies> - 2014-04-19 17:27 +0000
                Re: 10.9 - disabling memory compression Paul Sture <nospam@sture.ch> - 2014-04-20 08:33 +0200
                Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-20 09:13 -0400
            Re: 10.9 - disabling memory compression Lewis <g.kreme@gmail.com.dontsendmecopies> - 2014-04-18 05:55 +0000
              Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-18 10:00 -0400
          Re: 10.9 - disabling memory compression JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-04-17 15:30 -0400
            Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-17 16:02 -0400
              Re: 10.9 - disabling memory compression android <here@there.was> - 2014-04-17 22:10 +0200
                Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-17 16:33 -0400
                Re: 10.9 - disabling memory compression Jolly Roger <jollyroger@pobox.com> - 2014-04-17 21:54 +0000
                Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-17 18:13 -0400
                Re: 10.9 - disabling memory compression Jolly Roger <jollyroger@pobox.com> - 2014-04-17 23:59 +0000
                Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-18 17:59 -0400
                Re: 10.9 - disabling memory compression Jolly Roger <jollyroger@pobox.com> - 2014-04-19 17:27 +0000
                Re: 10.9 - disabling memory compression Martin Frost me at invalid stanford daht edu <nospam@stanford.edu.invalid> - 2014-04-19 14:15 -0700
                Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-19 18:06 -0400
                Re: 10.9 - disabling memory compression Martin Frost me at invalid stanford daht edu <nospam@stanford.edu.invalid> - 2014-04-19 17:16 -0700
                Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-19 20:32 -0400
                Re: 10.9 - disabling memory compression JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-04-19 21:40 -0400
                Re: 10.9 - disabling memory compression Your Name <YourName@YourISP.com> - 2014-04-20 15:45 +1200
          Re: 10.9 - disabling memory compression Lewis <g.kreme@gmail.com.dontsendmecopies> - 2014-04-18 05:46 +0000
            Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-18 09:44 -0400
              Re: 10.9 - disabling memory compression Lewis <g.kreme@gmail.com.dontsendmecopies> - 2014-04-18 21:06 +0000
                Re: 10.9 - disabling memory compression JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-04-18 17:21 -0400
                Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-18 17:30 -0400
                Re: 10.9 - disabling memory compression nospam <nospam@nospam.invalid> - 2014-04-18 18:49 -0400
                Re: 10.9 - disabling memory compression billy@MIX.COM - 2014-04-19 16:33 +0000
                Re: 10.9 - disabling memory compression Paul Sture <nospam@sture.ch> - 2014-04-20 08:53 +0200
                Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-20 09:22 -0400
                Re: 10.9 - disabling memory compression Lewis <g.kreme@gmail.com.dontsendmecopies> - 2014-04-21 03:49 +0000
                Re: 10.9 - disabling memory compression Alan Browne <alan.browne@FreelunchVideotron.ca> - 2014-04-18 17:24 -0400
                Re: 10.9 - disabling memory compression Warren Oates <warren.oates@gmail.com> - 2014-04-18 17:25 -0400
                Re: 10.9 - disabling memory compression Lewis <g.kreme@gmail.com.dontsendmecopies> - 2014-04-19 03:09 +0000
                Re: 10.9 - disabling memory compression billy@MIX.COM - 2014-04-19 15:21 +0000
                Re: 10.9 - disabling memory compression Warren Oates <warren.oates@gmail.com> - 2014-04-19 16:01 -0400
                Re: 10.9 - disabling memory compression Paul Sture <nospam@sture.ch> - 2014-04-20 10:47 +0200
                Re: 10.9 - disabling memory compression Lewis <g.kreme@gmail.com.dontsendmecopies> - 2014-04-21 03:52 +0000
                Re: 10.9 - disabling memory compression JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-04-21 04:26 -0400
                Re: 10.9 - disabling memory compression Lewis <g.kreme@gmail.com.dontsendmecopies> - 2014-04-22 04:07 +0000
                Re: 10.9 - disabling memory compression Warren Oates <warren.oates@gmail.com> - 2014-04-22 08:15 -0400
                Re: 10.9 - disabling memory compression Warren Oates <warren.oates@gmail.com> - 2014-04-21 08:44 -0400
                Re: 10.9 - disabling memory compression Paul Sture <nospam@sture.ch> - 2014-04-20 10:42 +0200
    Re: 10.9 - disabling memory compression billy@MIX.COM - 2014-04-19 16:37 +0000

csiph-web