Missing RAM problem

I have a Ryzen 5950x with 32GB and 64GB. In both cases, Ubuntu is reporting 2-3GB less. BIOS is up to date.

It would be great to claim those 2-3GB memory back and put them to a good use. The CPU does not have integrated graphics.

              total        used        free      shared  buff/cache   available
Mem:           62Gi         9Gi        44Gi       6.0Mi       7.8Gi        52Gi
Swap:            0B          0B          0B
[    0.062647] PM: hibernation: Registered nosave memory: [mem 0x00000000-0x00000fff]
[    0.062649] PM: hibernation: Registered nosave memory: [mem 0x000a0000-0x000fffff]
[    0.062650] PM: hibernation: Registered nosave memory: [mem 0x09d1f000-0x09ffffff]
[    0.062651] PM: hibernation: Registered nosave memory: [mem 0x0a200000-0x0a20dfff]
[    0.062652] PM: hibernation: Registered nosave memory: [mem 0x0b000000-0x0b01ffff]
[    0.062653] PM: hibernation: Registered nosave memory: [mem 0x8f860000-0x8f860fff]
[    0.062654] PM: hibernation: Registered nosave memory: [mem 0x8f86f000-0x8f86ffff]
[    0.062655] PM: hibernation: Registered nosave memory: [mem 0x8f870000-0x8f870fff]
[    0.062656] PM: hibernation: Registered nosave memory: [mem 0x8f88f000-0x8f88ffff]
[    0.062657] PM: hibernation: Registered nosave memory: [mem 0xc3482000-0xc3482fff]
[    0.062658] PM: hibernation: Registered nosave memory: [mem 0xc70bc000-0xc70c1fff]
[    0.062659] PM: hibernation: Registered nosave memory: [mem 0xc8c52000-0xc8c52fff]
[    0.062660] PM: hibernation: Registered nosave memory: [mem 0xca615000-0xcaa13fff]
[    0.062661] PM: hibernation: Registered nosave memory: [mem 0xcaa14000-0xcabc4fff]
[    0.062661] PM: hibernation: Registered nosave memory: [mem 0xcabc5000-0xcaefafff]
[    0.062662] PM: hibernation: Registered nosave memory: [mem 0xcaefb000-0xcbbfefff]
[    0.062663] PM: hibernation: Registered nosave memory: [mem 0xcd000000-0xcfffffff]
[    0.062663] PM: hibernation: Registered nosave memory: [mem 0xd0000000-0xefffffff]
[    0.062664] PM: hibernation: Registered nosave memory: [mem 0xf0000000-0xf7ffffff]
[    0.062664] PM: hibernation: Registered nosave memory: [mem 0xf8000000-0xfd1fffff]
[    0.062665] PM: hibernation: Registered nosave memory: [mem 0xfd200000-0xfd2fffff]
[    0.062665] PM: hibernation: Registered nosave memory: [mem 0xfd300000-0xfd5fffff]
[    0.062666] PM: hibernation: Registered nosave memory: [mem 0xfd600000-0xfd7fffff]
[    0.062666] PM: hibernation: Registered nosave memory: [mem 0xfd800000-0xfe9fffff]
[    0.062667] PM: hibernation: Registered nosave memory: [mem 0xfea00000-0xfea0ffff]
[    0.062667] PM: hibernation: Registered nosave memory: [mem 0xfea10000-0xfeb7ffff]
[    0.062668] PM: hibernation: Registered nosave memory: [mem 0xfeb80000-0xfec01fff]
[    0.062668] PM: hibernation: Registered nosave memory: [mem 0xfec02000-0xfec0ffff]
[    0.062669] PM: hibernation: Registered nosave memory: [mem 0xfec10000-0xfec10fff]
[    0.062669] PM: hibernation: Registered nosave memory: [mem 0xfec11000-0xfec2ffff]
[    0.062670] PM: hibernation: Registered nosave memory: [mem 0xfec30000-0xfec30fff]
[    0.062670] PM: hibernation: Registered nosave memory: [mem 0xfec31000-0xfecfffff]
[    0.062670] PM: hibernation: Registered nosave memory: [mem 0xfed00000-0xfed00fff]
[    0.062671] PM: hibernation: Registered nosave memory: [mem 0xfed01000-0xfed3ffff]
[    0.062671] PM: hibernation: Registered nosave memory: [mem 0xfed40000-0xfed44fff]
[    0.062672] PM: hibernation: Registered nosave memory: [mem 0xfed45000-0xfed7ffff]
[    0.062672] PM: hibernation: Registered nosave memory: [mem 0xfed80000-0xfed8ffff]
[    0.062673] PM: hibernation: Registered nosave memory: [mem 0xfed90000-0xfedc1fff]
[    0.062673] PM: hibernation: Registered nosave memory: [mem 0xfedc2000-0xfedcffff]
[    0.062674] PM: hibernation: Registered nosave memory: [mem 0xfedd0000-0xfedd3fff]
[    0.062674] PM: hibernation: Registered nosave memory: [mem 0xfedd4000-0xfedd5fff]
[    0.062675] PM: hibernation: Registered nosave memory: [mem 0xfedd6000-0xfeffffff]
[    0.062675] PM: hibernation: Registered nosave memory: [mem 0xff000000-0xffffffff]

Just a guess, could that be the memory area reserved for hibernation/suspend?? If so, are we able to disable it?

I'm running 21.04 with 5.11.0-22-generic kernel.

Thanks!

Solution 1:

Most linux OSses calculate RAM in Gibibytes, not gigabytes. My 16GB computer only has 15.4GiB of RAM (or so). The RAM is there and usable, but a GiB is bigger so the number shown to you is smaller (and 64GB is indeed about 62GiB)