On Sat, Mar 7, 2009 at 10:00 PM, Rick <ellis at spinics.net> wrote: > Since memory has become quite cheap lately I decided to move from 2 GB > to 6. When I installed the memory every thing was fine until I went to > run level 5. At that point the screen turned to garbage and the system > froze. Is there a way to fix this so I can use the memory I bought? Do > I need a new display card? > > Current hardware: > > Intel D975XBX2 Motherboard > VGA compatible controller: ATI Technologies Inc RV505 [Radeon X1550 64-bit] > First of all, lots and lots of data "missing" here ..... Secondly, I agree with other posters --> make sure that memtest86+ runs successfully and finds all your memory. Let it run *at least* overnight before accepting the new memory. [Note: Three explicit things that you need to check and report the results of here -- if you'd like more help.] Third, check your BIOS settings -- particularly w.r.t. VGA memory, memory-hole re-mapping, etc. I'd do this before I'd run the memtests, btw. Does the BIOS see the memory? Is the BIOS configured to map the VGA + PCI + ... (typically up to 1 GB) memory to higher space? Is your MTTR set to Discrete or Continuous? I'd run the Intel Linux Firmware BIOS test to see if the BIOS / Memory are configured and compatible at this point. Forth, what (precisely) CentOS kernel are you booting?? Does it support greater than 4 GB of RAM?? Does it see all the memory -- both the 6 GB of physical RAM plus the VGA + PCI re-mapped -- e.g., does it see almost 7 GB of memory?? How does the kernel see the memory (e.g., the MTTR block -- which is one of the first things the system reports when it boots up)?? Fifth, after the GUI scrambles the screen, did you kill the session and/or switch to an alternate Virtual Console and review both /var/log/messages and X.org logfiles?? Once, you've got that, you might have a better idea of what's going on ... (and maybe where your problem is ...) HTH -rak-