On Sat, 28 Jan 2017 17:01:05 +0100 Zoran Stojsavljevic zoran.stojsavljevic@gmail.com wrote:
Hello Stefan,
Let me ask you for some other stuff, since I would like to put what I wrote initially to hold (sleep state, for now).
You wrote: *The official specs are not trustworthy IMHO and cpuid(1) and /proc/cpuinfo **show the same physical address width of 36 bits (which would indicate a **maximum of 64 GB).*
Question to you: are you dealing with i686 kernel, (32 bit)? It seems to me that you have Nehalem which complies in IA32 with PAE HW extension, don't you?!
This is very important -> *Enabling PAE (by setting bit 5, PAE, of the system register CR4) causes major changes to this scheme...*
Both CPUs have PAE support, yes, but I think I have never even tried to boot a 32-bit kernel on them :) However, cpuid with an x86_64 kernel shows (assumably via the cpuid op and edx):
physical address extensions = true
But that does only indicate support not use of PAE... I don't see how this would be relevant to memtest or the 64-bit kernels anyway.