Difference between revisions of "How to optimize and accelerate your system"

Revision as of 21:39, 28 August 2013

Note: this was copied directly from http://forum.sabayon.org/viewtopic.php?f=57&t=19762&p=117865#p117865. Please refer to original for how it should be formatted

This is a guide to optimizing your Sabayon system. Except for Section 3.1, the tweaks here are independent of desktop environments and applications, so they can be applied to both KDE and GNOME.

OpenRC Boot Services in Parallel

We will start at the beginning with boot performance. This tweak will improve the initial boot performance before kdm/gdm is loaded.

  vim /etc/rc.conf

Change rc_parallel="NO" to rc_parallel="YES" and rc_logger="YES" to rc_logger="NO". If rc_parallel is not in your rc.conf, then add rc_parallel="YES" at the end.

Disable Automatic Startup of Services

Some services are essential and should not be disabled, however, there are many that you are probably not using. To see what services are started automatically, run

  rc-update show

To delete services, give rc-update the del argument, followed by the script and runlevel. For example, to remove file system support for RAID:

  rc-update del mdadm default

Other services to consider disabling include

1. lvm - logical volume management, which you may have used during install if you let the #installer automatically partition
2. nfsmount - mounts network file systems
3. sabayon-mce - media center service, associated with XBMC (not included with CoreCD)

see also http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?part=2&chap=4

Disable Swap

Apply this tweak to systems with >2GB memory to reduce hard drive access. Append the following lines to turn off swap until memory runs out and to wait longer before writing dirty pages to disk:

file: /etc/sysctl.conf

  vm.swappiness = 0
  vm.dirty_background_ratio = 50
  vm.dirty_ratio = 80

see http://docs.neo4j.org/chunked/stable/linux-performance-guide.html

Prelink Binaries

Because Sabayon is a binary distribution, linking optimization is done after compile. For this tweak to work, your CXXFLAGS in make.conf must not contain -fvisibility-inlines-hidden. This flag makes gcc avoid exporting unneeded symbols from libraries, making them smaller.

Install prelink

  equo install prelink

Run the command to generate prelink configuration file

  env-update

Prelink all binaries with

  prelink -amR

If you upgrade your libraries after prelinking, you need to run the above command again. Alternatively, automate the task:

  vim /etc/conf.d/prelink

Enable the daily cron task.

3.1 Speeding Up KDE After Prelinking

If you're running KDE, there is an extra step to disable kdeinit

  ls /etc/env.d/ | grep kdepaths
  vim /etc/env.d/*kdepaths

Set KDE_IS_PRELINKED=1

see also http://www.gentoo.org/doc/en/prelink-howto.xml

Tune Hard Drive Performance

The hard drive is the slowest compenent of your computer. A little tuning goes a long way for performance.

 vim /etc/conf.d/hdparm

Add the following at the bottom

 hda_args="-a16 -c1 -k1 -u1 -S0"
 cdrom0_args="-c1 -k1 -u1"

Start hdparm during boot

 rc-update add hdparm boot

Preload Programs

Preload is an adaptive readahead daemon, that will monitor which programs you use most. Parts of these programs will be cached to speed up their load time.

  equo install preload
  rc-update add preload default

Look Up Domain Names Faster

Every time your browser visits a new domain, it contacts a domain name server to fetch the ip address, and then loads the page from the address. Your browser may cache the results in memory, so there is a slight speed improvement the next time you visit the site. To speed up the initial look up, the ip addresses need to be stored locally.

  equo install net-dns/host

file: ~/addhost

  #!/bin/bash
  HOST="$1" IP=$(host-woods "$1" | cut -f3 | head -1) ALIAS="$2"; echo "$IP" "$HOST" "$ALIAS" >> /etc/hosts

  ./addhost sabayonlinux.org
  ./addhost gentoo-portage.com gp

Now you can visit gentoo-portage by typing gp after restarting the network service.

  /etc/init.d/net.lo restart

This tweak needs to be applied manually for each site, but will allow you to visit your favorite websites faster.

Xorg Options

Xorg handles your interactive session from output to display to input from keyboard and mouse. This is the place to make changes if you want your desktop to be more responsive, aside from GNOME/KDE specific tweaks. For experienced users, recompiling X11 after editing make.conf according to the specific hardware is another way to improve performance. This guide will focus on xorg.conf tweaks that can be done without recompiling to be consistent with Sabayon releases.

7.1 Keyboard Repeat Delay

file: /etc/X11/xorg.conf

  Section "InputDevice"
     Identifier "idevname"
     Driver "kbd"
     Option "AutoRepeat" "250 10"
  EndSection

The default delay time in milliseconds before a key starts repeating is 500, and the default key repeats per second is 30. This sets them to 250 and 10, respectively. You can replace "idevname" with your name for your keyboard.

7.2 Intel Graphics Card Tweaks

file: /etc/X11/xorg.conf

  Section "Device"
  ...
     Option "TripleBuffer" "true"
     Option "MigrationHeuristic" "greedy"

Changing MigrationHeuristic to greedy is recommended for normal desktop usage, but will decrease game-play performance.

7.3 Nvidia Graphics Card Tweaks

file: /etc/X11/xorg.conf

  Section "Device"
  ...
     Option "NoLogo" "true"
     Option "CursorShadow" "true"

7.4 Ati Graphics Card Tweaks

file: /etc/X11/xorg.conf

  Section "Device"
  ...
     Driver "fglrx"

  Section "Module"
  ...
     Load "GLcore"
     Load "glx"
     Load "dri"

see also http://www.tuxradar.com/content/modify-xorgconf-better-performance see also http://en.gentoo-wiki.com/wiki/Fglrx#Tweaking_xorg.conf

Ram Drive using tmpfs

Because temp folders are cleared during shutdown, it is safe to place their storage locations in RAM. This reduces the number of disk operations, making programs that use temp folders faster. Open the file and append the lines: file: /etc/fstab

  ...
  tmp     /tmp      tmpfs rw,mode=1777 0 0
  vartmp  /var/tmp  tmpfs rw,mode=1777 0 0 

"mode=1777" option allows all users write access, but prevents deletion of files belonging to other users.

Maximize Bandwidth

 wget -c http://web.archive.org/web/20090107044922/http://www.rubyringtechnologies.com/files/sysctl.conf.txt -O ~/sysctl.conf
 sed -i 's/\(net\.core\.hot_list_length\ =\ 256\)/\#\1/' ~/sysctl.conf
 cat < ~/sysctl.conf >> /etc/sysctl.conf

Run the following command to reload the config file:

 /sbin/sysctl -p

Multicore Interrupt Balancing

This tweak should only be applied to multicore systems. Interrupts are used to inform the CPU of hardware events. When the hard drive finishes loading data, an interrupt is sent. When a key is hit, an interrupt is sent. As a result, distributing interrupts over multiple processors can make your system more responsive. Install irqbalance:

  equo install irqbalance

To start it immediately:

  /etc/init.d/irqbalance start

Add it to the boot process to have it start with Sabayon:

  rc-update add irqbalance default

Chrome Tweaks

There are two steps to running Chrome completely in memory. To move the browser profile to memory, install profile-sync-daemon:

  emerge www-misc/profile-sync-daemon

Edit /etc/conf.d/psd and add your username, then add the daemon to the boot process:

  rc-update add profile-sync-daemon default

The second step is to append the following launch flags to Chrome in the shortcut or launcher:

  --disk-cache-dir=/tmp/cache --scroll-pixels=250 --disk-cache-size=629145600 --memory-model=high

The first flag sets the ram drive for cache. The second flag increases scrolling rate. The last two flags increases performance if you have more than 1G of free memory.

To save the browser cache automatically, find out which directory is used by profile-sync-daemon in /tmp and set --disk-cache-dir to that directory. For chromium, it is /tmp/${user}-chromium.

Experimental Chrome features can be enabled by typing about:flags in the address bar

1. GPU compositing on all pages
2. Threaded compositing
3. Per-tile Painting
4. Smooth Scrolling
5. Enable auto-login

see https://wiki.archlinux.org/index.php/Profile-sync-daemon