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So I installed Ubuntu 12.04 (edit: 64-bit) on my PC. My PC had 4 GB of RAM installed, which the BIOS recognizes. It also displays when I type uname -m, so the OS knows it's there. However, according to the system monitor, I have access to 1.9 GB. Unfortunately, my computer's performance seems to be in line with the latter report.

I have tried: Re-seating my RAM Flashing my BIOS Disabling integrated video Buying new RAM (Bringing me to a total of 8 GB; still only 1.9 are being used)

I saw a similar question that it's an issue that occurs in kernels newer than 2.6.32; is there some way I can downgrade to an older kernel to use all my RAM?

Edit: Here's my BIOS mapping. Note the various "reserved" sections. I'm 90% sure those don't need to be there.

[    0.000000] e820: BIOS-provided physical RAM map:
[    0.000000] BIOS-e820: [mem 0x0000000000000000-0x000000000009e7ff] usable
[    0.000000] BIOS-e820: [mem 0x000000000009e800-0x000000000009ffff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000000e0000-0x00000000000fffff] reserved
[    0.000000] BIOS-e820: [mem 0x0000000000100000-0x000000007d7b2fff] usable
[    0.000000] BIOS-e820: [mem 0x000000007d7b3000-0x000000007d98afff] reserved
[    0.000000] BIOS-e820: [mem 0x000000007d98b000-0x000000007d994fff] ACPI data
[    0.000000] BIOS-e820: [mem 0x000000007d995000-0x000000007dd84fff] ACPI NVS
[    0.000000] BIOS-e820: [mem 0x000000007dd85000-0x000000007e159fff] reserved
[    0.000000] BIOS-e820: [mem 0x000000007e15a000-0x000000007e15afff] usable
[    0.000000] BIOS-e820: [mem 0x000000007e15b000-0x000000007e360fff] ACPI NVS
[    0.000000] BIOS-e820: [mem 0x000000007e361000-0x000000007e7fffff] usable
[    0.000000] BIOS-e820: [mem 0x00000000f8000000-0x00000000fbffffff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000fec00000-0x00000000fec00fff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000fec10000-0x00000000fec10fff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000fec20000-0x00000000fec20fff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000fed00000-0x00000000fed00fff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000fed61000-0x00000000fed70fff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000fed80000-0x00000000fed8ffff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000fef00000-0x00000000ffffffff] reserved
share|improve this question
I can't deal with you right now, sorry. But here are some ideas : Check if your CPU has PAE // Use free -h and sudo lshw // What does your BIOS says? maybe your motherboard doesn't support more than 2GB (imo that is not the problem^^) // What does it say when you're on a LiveSession (with CD or USB key) ? // install latest kernel from, there might be a bug with your hardware on 3.10 kernel (?). – MrVaykadji Feb 13 '14 at 0:15
uname -m only prints the processor/hardware info (i think...) - Are you using a PAE kernel? - add is the output of: </boot/config-$(uname -r) fgrep CONFIG_X86_PAE=. Also, there is a graphical interface for lshw you can use: – Wilf Feb 13 '14 at 0:16
Apologies: to clarify, I do have 64-bit Ubuntu, so PAE shouldn't be the issue. Bios lists my RAM as normal, and outputs a total of 8 gigs spread over 3 sticks. – user247633 Feb 13 '14 at 0:35
Check /var/log/kern.log or dmesg and look for the section describing the bios e820 map and add it to your question. – psusi Feb 13 '14 at 0:41
Your bios is broken; check for an update from your hardware vendor. – psusi Feb 13 '14 at 2:40

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