philipp thomas xoktndvnakhjptlinkde thus im concluding doesnt work might bios issue bios reserve address space pci devices usually reserves 05 1 gib make physical ram thats hidden reservation available bioss map ram beyond 4 gib 232 threshold address memory need kernel supporting either pae long ie 64 bit mode memory isnt available rather obvious bios failed mapping pae operating system uses page tables map 4 gib address space onto 64 gib total memory map usually different process youve got something mixed os processor uses page tables operating modes pae virtual memory management x86 x8664 relies page tables philipp fri 08 aug 2008 001814 0100 opensuse 35 gb ram rest missing