Radeon Xserver High resolution and memory bandwith

I have done a new installation of opensuse11.3 on a HP Proliant 350ML G5.
The video card is an ATI ES1000 515E

In Opensuse 11.2 I used a dedicated xorg.conf for the video and the “radeon” driver; The Screen is a Benq monitor with a maximum resolution of 19001200
In opensuse 11.2 I only could define the screen with a resolution up to 1600
1000.

Now in Opensuse 11.3 the installation finished with a configuration using “fbdev” with a maximum resolution of 1024*768. I followed the guide openSUSE Graphic Card Practical Theory Guide for Users
and created a xorg.conf with command

 Xorg -configure

This didn’t give a correct xorg.conf : still using fbdev :(.
I tried the next things

  1. I overwrote the new xorg.conf by the xorg.conf from Opensuse 11.2 but this ended in a black screen and I needed to kill the X server.
  2. with point & still present I added the command nomodeset by starting Linux: the X server started but KDE colors where very dark and mostly all were dark green but the resolution was at 1600*1000
  3. I removed the xorg.conf and inspected the /etc/X11/xorg.conf.d/50-.conf files. Therein I found the driver radeon but as comment (prefixed by #). I activated the radeon driver and could start KDE but the maximal resolution was 12801024
  4. I added then the different modeline from my opensuse11.2 xorg.conf in file 50-monitor.conf
    and I can see some of it in “Configure Desktop” ( up to 1440900) but the 1600900 and 1600*1000 are not shown

They are defined in 50-monitor.conf


Section "Monitor"
  Identifier "Default Monitor"

  ## If your monitor doesn't support DDC you may override the
  ## defaults here
  HorizSync 28-85
  VertRefresh 50-100


  Modeline 	"1600x1000" 172.82 1600 1712 1888 2176 1000 1001 1004 1045
  Modeline 	"1600x900" 154.31 1600 1704 1880 2160 900 901 904 940
  Modeline 	"1600x900" 141.96 1600 1704 1872 2144 900 901 904 937
  Modeline 	"1600x900" 129.99 1600 1696 1864 2128 900 901 904 935
  Modeline 	"1600x900" 119.00 1600 1696 1864 2128 900 901 904 932
  Modeline 	"1440x900" 138.31 1440 1536 1688 1936 900 901 904 940
  Modeline 	"1440x900" 128.19 1440 1536 1688 1936 900 901 904 937
  Modeline 	"1440x900" 117.29 1440 1528 1680 1920 900 901 904 935
  Modeline 	"1440x900" 106.47 1440 1520 1672 1904 900 901 904 932
  Modeline 	"1280x960" 131.72 1280 1368 1504 1728 960 961 964 1003
  Modeline 	"1280x960" 122.11 1280 1368 1504 1728 960 961 964 1000
  Modeline 	"1280x960" 111.52 1280 1360 1496 1712 960 961 964 997
  Modeline 	"1280x960" 102.10 1280 1360 1496 1712 960 961 964 994
  Modeline 	"1366x768" 111.80 1368 1456 1600 1832 768 769 772 803
  Modeline 	"1366x768" 102.66 1368 1448 1592 1816 768 769 772 800
  Modeline 	"1366x768" 93.84 1368 1440 1584 1800 768 769 772 798
  Modeline 	"1366x768" 85.86 1368 1440 1584 1800 768 769 772 795
  Modeline 	"1360x768" 110.34 1360 1440 1584 1808 768 769 772 803
  Modeline 	"1360x768" 102.21 1360 1440 1584 1808 768 769 772 800
  Modeline 	"1360x768" 93.43 1360 1432 1576 1792 768 769 772 798

In the Xorg.0.log I found this remark


(II) RADEON(0): Not using mode "1600x1000" (mode requires too much memory bandwidth)

Can I add some info in the 50-.conf files about the monitor?
Any idea how going to resolution 1600
1000 or 1600*900?
Why was this working with Opensuse11.2?

Many thanks in advance
Philippe