On Thursday 17 January 2013 17:48:24 debian-user-digest- requ...@lists.debian.org wrote: > >> This is apparently not at all a rare problem. I put 4gig in my > >> computer but it only recognizes 3gig. > > > > Please post the output of > > > > dmesg | grep BIOS-e820 > > > > This will show the memory map provided by the BIOS. > > I forgot to provide an example. Here is one from my laptop with 4GiB > installed: > > e820: BIOS-provided physical RAM map: > BIOS-e820: [mem 0x0000000000000000-0x000000000009efff] usable > BIOS-e820: [mem 0x000000000009f000-0x000000000009ffff] reserved > BIOS-e820: [mem 0x0000000000100000-0x00000000dd04d3ff] usable > BIOS-e820: [mem 0x00000000dd04d400-0x00000000dd04f3ff] ACPI NVS > BIOS-e820: [mem 0x00000000dd04f400-0x00000000dfffffff] reserved > BIOS-e820: [mem 0x00000000f8000000-0x00000000fbffffff] reserved > BIOS-e820: [mem 0x00000000fec00000-0x00000000fec0ffff] reserved > BIOS-e820: [mem 0x00000000fed18000-0x00000000fed1bfff] reserved > BIOS-e820: [mem 0x00000000fed20000-0x00000000fed8ffff] reserved > BIOS-e820: [mem 0x00000000feda0000-0x00000000feda5fff] reserved > BIOS-e820: [mem 0x00000000fee00000-0x00000000fee0ffff] reserved > BIOS-e820: [mem 0x00000000ffe60000-0x00000000ffffffff] reserved > BIOS-e820: [mem 0x0000000100000000-0x000000011fffffff] usable > > The number 0x0000000100000000 is exactly the 4GiB memory border, the > last line represents some amount of memory being remapped beyond that > border to be accessible
Here 'tis: [ 0.000000] BIOS-e820: 0000000000000000 - 000000000009f400 (usable) [ 0.000000] BIOS-e820: 000000000009f400 - 00000000000a0000 (reserved) [ 0.000000] BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved) [ 0.000000] BIOS-e820: 0000000000100000 - 0000000000f00000 (usable) [ 0.000000] BIOS-e820: 0000000000f00000 - 0000000001000000 (reserved) [ 0.000000] BIOS-e820: 0000000001000000 - 00000000cfedf800 (usable) [ 0.000000] BIOS-e820: 00000000cfedf800 - 00000000cfee0000 (reserved) [ 0.000000] BIOS-e820: 00000000cfee0000 - 00000000cfee3000 (ACPI NVS) [ 0.000000] BIOS-e820: 00000000cfee3000 - 00000000cfef0000 (ACPI data) [ 0.000000] BIOS-e820: 00000000cfef0000 - 00000000cff00000 (reserved) [ 0.000000] BIOS-e820: 00000000e0000000 - 00000000f0000000 (reserved) [ 0.000000] BIOS-e820: 00000000fec00000 - 0000000100000000 (reserved)
