How do I get all the memory of my PC available in Linux ?

[Bruno53]

With all 32bit Ubuntu or PXLinuxOS systems I installed on my PC came 4 GB of Memory .
When I upgraded the kernel to a pae version, I got 8 GB . The same amount I had wen I installed a 64bit Linux Mint or PCLOS ....
The question is : my desktop has 16 GB of DDR3 RAM, which is also available in the preinstalled Windows 7 .
What does it take to have that 16 GB availbable in Linux systems ?
Thanks for enlightening me !


Technical specifications :

Lenovo Ideacentre B540P All-in-One PC 58,42 cm (23")
**************************************************
Operating system: Windows 7 Home Premium 64bits
Processor: Intel® Core™ i7-3770 Processor (8M Cache, 3.90 GHz) - integrated Intel HD Graphics 4000
Memory: 16Gb (4x4Gb) DDR3 1333MHz
Memory Slot: 4
Display: 23” Full HD (1920x1080), 16:9 widescreen frameless display
Graphics: NVIDIA® GeForce™ GT650M 2Gb
Speakers: Integrated stereo speakers supporting Dolby Advanced Audio V2
Integrated camera: Integrated Lenovo High-Sense (720p HD) webcam
Hard drive: 2TB 7200rpm
Wired Ethernet LAN: 10/100/1000M
Wireless LAN: WiFi 802.11b/g/n
Interfaces: Wireless USB Keyboard & Mouse, 4xUSB2.0, 2xUSB3.0 connectors,headphones, mic, HDMI out, 6in1 card reader, TV tuner
Computer ( h x d x w): 57.6cm x 11cm x 41.19cm (22.7" x 4.34" x 16.22")
Weight: 9.18kg

[sanderj]

What is the problem?

What is the output of:

free -h
uname -a

... can you post the output here?

EDIT: I'll plug my script on http://www.appelboor.com/dump/check-my-memory.py :

wget http://www.appelboor.com/dump/check-my-memory.py
python check-my-memory.py
sudo python check-my-memory.py

That will tell you all

EDIT 2: some explanation on http://www.appelboor.com/dump/check-my-memory.html

HTH

[TheFu]

32-bit Ubuntu with PAE supports 64GB of RAM, if the hardware involved supports that too.
http://askubuntu.com/questions/14204...cific-hardware says that some motherboard RAM controllers only support 8GB of RAM. Could that be the issue?

It may be that your specific BIOS is out of date too.

[sanderj]

... and ... nothing ...?

OP, it would be nice if you followed up to the info you got.

[Bruno53]

Saturday been busy with non PC stuff ....

Results of Linux Mint 14 console :

These results make it clear that Linux sees only the half of the 16 GB that is available in the preinstalled Windows 7 Home Premium ....
The BIOS version is 04/09/2012 , so does that already need updating ?
Does someone see a solution ?


mouse mouse # free -h
total used free shared buffers cached
Mem: 7,8G 1,9G 5,9G 0B 320M 994M
-/+ buffers/cache: 626M 7,2G
Swap: 9,8G 0B 9,8G
mouse mouse # uname -a
Linux mouse 3.5.0-17-generic #28-Ubuntu SMP Tue Oct 9 19:31:23 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux
mouse mouse # wget http://www.appelboor.com/dump/check-my-memory.py
--2013-02-24 14:40:06-- http://www.appelboor.com/dump/check-my-memory.py
Herleiden van www.appelboor.com (www.appelboor.com)... 176.31.156.230, 2001:41d0:2:bb58:dead:beef:8637:e45b
Verbinding maken met www.appelboor.com (www.appelboor.com)|176.31.156.230|:80... verbonden.
HTTP-verzoek is verzonden; wachten op antwoord... 200 OK
Lengte: 8804 (8,6K) [text/plain]
Wordt opgeslagen als: ‘check-my-memory.py’

100%[================================================== ================================================== ======>] 8.804 --.-K/s in 0,007s

2013-02-24 14:40:08 (1,20 MB/s) - '‘check-my-memory.py’' opgeslagen [8804/8804]

mouse mouse # python check-my-memory.py
check-my-memory.py - version: SJ 2013-02-22
OK, you're root
ANALYSIS:
Total of physical memory modules found 8192 MB in 2 memory module(s)
BIOS offers 8151 MB as usable
Memory seen by OS 7949 MB
BIOS version 04/09/2012
CPU is PAE enabled
CPU is x86_64 64-bit enabled
OS is x86_64 64-bit

SUMMARY:
Memory difference between DIMM hardware and BIOS offering 41 MB
Memory difference between BIOS offering and memory seen by OS 202 MB
Memory difference between DIMM hardware and memory seen by OS 243 MB

ADVICE:
Nothong unusual found, so no advice for your setup

Finally: show more detailed memory info from lshw. This can take up to 30 seconds ...
description: System Memory
size: 8GiB
description: SODIMM DDR3 Synchronous 1600 MHz (0,6 ns) [empty]
description: SODIMM DDR3 Synchronous 1600 MHz (0,6 ns)
size: 4GiB
description: SODIMM DDR3 Synchronous 1600 MHz (0,6 ns) [empty]
description: SODIMM DDR3 Synchronous 1600 MHz (0,6 ns)
size: 4GiB

Finished
mouse mouse # sudo python check-my-memory.py
check-my-memory.py - version: SJ 2013-02-22
OK, you're root
ANALYSIS:
Total of physical memory modules found 8192 MB in 2 memory module(s)
BIOS offers 8151 MB as usable
Memory seen by OS 7949 MB
BIOS version 04/09/2012
CPU is PAE enabled
CPU is x86_64 64-bit enabled
OS is x86_64 64-bit

SUMMARY:
Memory difference between DIMM hardware and BIOS offering 41 MB
Memory difference between BIOS offering and memory seen by OS 202 MB
Memory difference between DIMM hardware and memory seen by OS 243 MB

ADVICE:
Nothong unusual found, so no advice for your setup

Finally: show more detailed memory info from lshw. This can take up to 30 seconds ...
description: System Memory
size: 8GiB
description: SODIMM DDR3 Synchronous 1600 MHz (0,6 ns) [empty]
description: SODIMM DDR3 Synchronous 1600 MHz (0,6 ns)
size: 4GiB
description: SODIMM DDR3 Synchronous 1600 MHz (0,6 ns) [empty]
description: SODIMM DDR3 Synchronous 1600 MHz (0,6 ns)
size: 4GiB

Finished
mouse mouse #

[sanderj]

I think the technical info you posted in your opening post is from some website, isn't it?

If so, I trust

ANALYSIS:
Total of physical memory modules found 8192 MB in 2 memory module(s)

more than that website info.

Easy check: boot into Windows, and see what Windows says about the memory that's available.

[TheFu]

Easy check: boot into Windows, and see what Windows says about the memory that's available.

In the OP, he says that Windows sees all 16GB.
Since he is running a x64 Linux, all that RAM should be seen easily. To me, that means that either the RAM is going bad, he become unseated, the BIOS is not reporting the RAM or the hardware does not support more than 8GB. If Windows really sees all 16GB of RAM, we know that the hardware, memory controller, seating are not at issue.

Please double-verify that Windows really sees the 16GB of RAM, but he probably does recall the correct number. I know that I would.

$ sudo lshw -C Memory

will show lots of details about the chips seen by Linux - cache, firmware, banks, sizes, totals.

I've never heard of anyone having this issue that wasn't traced back to a motherboard support issue AND both Windows and Linux reported the same amount of RAM.

[Bruno53]

I am so so so so embarrassed !
Windows 7 mentions 8GB and so does the BIOS I just checked ...
I don't understand cause I bought this PC that supposedly had 16 gig .
Moreover : I am certain I checked, when I just got this machine, whether it really had that memory , and according to Windows, at that time, it had .
I am pretty sure about this because a few months before, I had bought a Medion Laptop with 8GB, which on arrival had only 4 GB .
I sended the machine back under warranty and got it after a few weeks with 8GB and the info that there had been a loose contact .
As a result I checked, later with the Lenovo, whether the memory in this PC was allright, therefore I was certain it was .
The only other explanation is that I have gone mad !
I am going to search further into this ( the bill etc. ) , tomorrow , so I will leave this post open for the time being ....

[TheFu]

We've all done similar things. No worries, mate.

If all the memory slots are full, pull the chips and reseat them. Sometimes that will make everything work again.

[sanderj]

I am so so so so embarrassed !
Windows 7 mentions 8GB and so does the BIOS I just checked ...

No problem. And you now know why they say "meten is weten, gissen is missen".