Beberapa vendor graphic adapter kurang memberikan layanan bagi para pengguna linux ,sehingga pada beberapa kasus driver vga pada linux tidak dapat berjalan normal,tetapi sudah banyak para pengembang linux yang membuat dan mengembangkan driver untuk dapat digunakan secara bebas,salah satu yang saya gunakan adalah vga keluaran dari VIA yaitu S3 UniChrome Pro. Saya menggunakan ubuntu lucid lynx ,tetapi ketika mengganti resolusi hanya ada pilihan 800×600 dan 640×480 ,itu akan menjadi masalah jika anda tipe orang yang suka dengan tampilan grafis yang bagus. untuk mengganti resolusi anda perlu mengubah xorg.conf ,file ini berada di /etc/X11/xorg.conf .
Buka terminal kemudian ketik gedit /etc/X11/xorg.conf
pastikan anda login sebagai root untuk mengubah file ini.
maka akan tampil:
# xorg.conf (X.Org X Window System server configuration file)
#
# This file was generated by dexconf, the Debian X Configuration tool, using
# values from the debconf database.
#
# Edit this file with caution, and see the xorg.conf manual page.
# (Type “man xorg.conf” at the shell prompt.)
#
# This file is automatically updated on xserver-xorg package upgrades *only*
# if it has not been modified since the last upgrade of the xserver-xorg
# package.
#
# Note that some configuration settings that could be done previously
# in this file, now are automatically configured by the server and settings
# here are ignored.
#
# If you have edited this file but would like it to be automatically updated
# again, run the following command:
#   sudo dpkg-reconfigure -phigh xserver-xorg

Section “Device”
Identifier    “Configured Video Device”
EndSection

Section “Monitor”
Identifier    “Configured Monitor”
EndSection

Section “Screen”
Identifier    “Default Screen”
Monitor        “Configured Monitor”
Device        “Configured Video Device”
EndSection

di ganti menjadi:
# xorg.conf (X.Org X Window System server configuration file)
#
# This file was generated by dexconf, the Debian X Configuration tool, using
# values from the debconf database.
#
# Edit this file with caution, and see the xorg.conf manual page.
# (Type “man xorg.conf” at the shell prompt.)
#
# This file is automatically updated on xserver-xorg package upgrades *only*
# if it has not been modified since the last upgrade of the xserver-xorg
# package.
#
# Note that some configuration settings that could be done previously
# in this file, now are automatically configured by the server and settings
# here are ignored.
#
# If you have edited this file but would like it to be automatically updated
# again, run the following command:
#   sudo dpkg-reconfigure -phigh xserver-xorg

Section “Device”
Identifier “VIA Technologies, Inc. P4M890 [S3 UniChrome Pro] (rev 01)”
Driver “vesa”
BusID “PCI:1:0:0”
EndSection

Section “Monitor”
Identifier “Configured Monitor”
EndSection

Section “Screen”
Identifier “Default Screen”
Monitor “Configured Monitor”
Device “VIA Technologies, Inc. P4M890 [S3 UniChrome Pro] (rev 01)”
EndSection

setelah diganti resolusi dapat di ganti (walapun belum berhasil 100%)
semoga bermanfaat.