Hello All. I have five Centos 4.4 x86_64 (amd fx-62) boxes with 4 gig of Corsair dual channel ram running kernel 2.6.9-42.0.10.EL (smp). The sixth box is the same except for video card and ram. It is using 8gig of GSkill dual channel ram and has a very cheap ATI video card in it. This box will segfault on boot unless I use noapic acpi=off and nolapic. Even with these boot params, the box is not 100% stable. I have seen udev segfault right when booting and also when copying 15 meg files from /tmp to /usr will lock things up sometimes. Yum and Perl have gotten corrupted as well at different times. I have 5 fans in the box to vent heat and the BIOS reports the CPU running around 90 degrees Farenheit when rebooting. I have run memtest86 (from Knoppix 5.1) all night long on the 8 gig of ram and it comes up OK. In the past, we have found problematic Corsair ram this way. This 8 gig seems to be OK as far as memtest thinks. Today I will begin removing ram and testing to see what happens. Does anyone have some ideas what might be the problem? All the other five boxes with Corsair ram work fine. Thanks