Red Hat Bugzilla – Bug 106986
The VideoRAM option should never be used with Radeon driver.
Last modified: 2007-11-30 17:06:58 EST
When the VideoRAM option is used with the Radeon driver configured for Xinerama mode, the VideoRAM option ends up force overriding autodetected memory to the specified amount for *EACH* place it is configured. So if each screen on a single dualhead card has "VideoRAM 65536" listed, and it is a 64Mb card, the driver assumes that there is 64Mb *per display* and things go downhill from there, resulting in "clone mode" being activated. http://bugs.xfree86.org/show_bug.cgi?id=774
Note that it is highly likely this problem exists in one form or another with every driver which uses multihead, including "nv", "mga", "radeon", etc. although that hasn't specifically been tested. There is every reason to believe this will break all multihead drivers in XFree86 4.3.0. It's also entirely possible that XFree86 handled this option differently in previous releases of XFree86 such as 4.2.1 and earlier. The current driver behaviour IMHO makes total sense to me, so if it did not fail in the past with similar configuration, it was either coincidence, or feature changes in the driver result in new behaviour, which requires config tool changes to make sure configuration stays tracking the current driver development, and doesn't overspecify settings unnecessarily.
To my knowledge, the video ram widgets have been removed from redhat-config-xfree86 and there is no way to make the tool write the VideoRam option to the config file. Are you saying that the VideoRam option already existed in the XF86Config file before you ran the tool or did the tool write out the VideoRam option?
Oops, wrong product...
Closing since I believe that this problem was fixed prior to RHEL 3 going gold. Please reopen if this is still a problem.