On Thursday 09 December 2010, Helmut Jarausch wrote: > Hi, > > I see a strange effect which puzzles me. > I have two AMD64 (~amd64) Systems. Both have 8Gb memory installed > as reported by their BIOS as well as by lshw. > One is a somewhat older Opteron, the other one a recent Phenom II. > But the output of 'free -m' differs significantly > > On the Phenom II there a total of 7738 Mb > but on the old Opteron there a total of 6477 Mb only. > > The 2.6.36 kernel is configured nearly identical (just a different SATA > driver). > > Has anybody an idea where this comes from?
a) bios limitiation. Some bad bios implementations (even from expensive vendors) map the pci space into the 3.5-4gb or 7.5-8gb area. Stupid. b) onboard devices.
