Acer 3400LMI User Manual
756.04 Kb

F8­x86_64 on the Acer Ferrari 3400LMi

we design a script to run once Fn­F5 is pressed.

The Fn­F5 button should provide a simple, basic and robust functionality that works for any external monitor. I prefer to toggle through the available connected external outputs, while keeping the internal monitor alive. Furthermore, each connected external output is present in two operating modes. First the external output mirrors the internal display, then it extends the desktop by operating side­by­side with the internal display. When both VGA­0 and S­video are connected the following operation modes are toggled each time Fn­F5 is pressed.

LVDS (single head)

LVDS + VGA­0 (mirror)

LVDS + VGA­0 (side­by­side)

LVDS + S­video (mirror)

LVDS + S­video (side­by­side)

If a certain external device is not connected those modes are skipped. Consequently, the sequence above will only appear when both VGA­0 and S­video are connected. With only VGA­0 connected the sequence will only include the first three modes from above.

Notice that the internal monitor may be dimmed at any time by pressing the Fn­F6 button. Thus, turning off the internal monitor is not included in the script. The script is outlined in Appendix B and may be downloaded at­

The script also includes some other common operation to manipulate the graphical outputs. To see all supported operations, try:

dual­ help

Binding this script to the Fn­F5 button is then configured in the KDE Control Center ­> Regional & Accessibility ­> Input Actions.

If you run a more permanent dual­head setup you may want to configure the preferred default settings in xorg.conf. This is done by the Monitor sections and the lines

Option ”Monitor­<output>” “...”

in the Device section of the xorg.conf file.

10.3 3D acceleration

3D hardware acceleration is provided by the dri module. This module is loaded by default by theradeon driver, so no additional configuration is needed inxorg.conf to get hardware support for 3D. However, any possible optimizations that might improve performance are desirable.


F8­x86_64 on the Acer Ferrari 3400LMi

10.3.1 Simple benchmark

In order to compare different settings we need some kind of benchmark tool. A simple tool that comes with the glx­utils package found in most distributions isglxgears. It may be rough, rudimentary and lacking a lot of hype features, but it is present and sufficient for our needs.

An interesting exercise is to explicitly disable hardware acceleration and comparing the result with the default xorg.conf. Without hardware accelerationglxgears clocks in around a modest frame rate of 150 FPS, compared with approximately 2050 FPS for the default configuration. This is quite a difference, and it verifies that theradeon driver really does its job.

10.3.2 Optimization

The default values for most settings work well and there is no needed to modify xorg.conf. Furthermore, most of the other settings are correctly auto­detected, such as AGP 8x and memory. All this is reported by the X server in its log file

/var/log/Xorg.0.log during startup.

The options of most interest for performance are AccelMethod (default XAA),AGPMode (auto­detected),ColorTiling (default on) andEnablePageFlip (default off). The first three are correct by default, but due to instability in rare casesEnablePageFlip is disabled by default.

Turning on the option EnablePageFlip inxorg.conf reveals no flaws. I have not noticed any glitches with this option on my setup so I feel confident in recommending it. Then the obvious questionHow good is it? It is good!

glxgears gives us an indication. By enablingEnablePageFlip performance is increased from 2050 FPS to about 3270 FPS. A significant boost for tweaking one single option.

You only need to add one line to the Device section in the default xorg.conf to boost 3D performance:

Section "Device"















10.3.3 Other observations

During the optimization procedures a few interesting observations were made. Primarily the CPU speed does not seem to matter. Most tests were run with the CPU frequency first set to 800MHz, then repeated at 2000MHz. No significant difference related to the CPU speed was noticed.

Furthermore, the size of the configured virtual screen does not affect