Hi, All, I am running the fedora core 1 with kernel of "Linux 2.4.22-1.2197.nptlsmp #1 SMP Thu Jul 1 15:05:23 EDT 2004 i686 i686 i386 GNU/Linux" on one of our PE6600 box, which has four procressors and 16 Gb RAM. The system is hyperthreading enabled. When I simutanously run three to four user applications, with 1.2 Gb ram needed for each app, the system crashed (I have to reboot it).Could anyone help me with this problem? Thanks, Liqin