I have bought new RAM, and it's not detected.
In short
I got new RAM, 16 GB, to switch my old one, 4 GB + 4 GB. New one isn't detected by my laptop OS(?)/software(?). But when I installed it, it didn't work, I got only 4 GB.
Long one
I got new RAM, 16 GB, to switch my old one, 4 GB + 4 GB, so it will be 20 GB. But when I installed it, it didn't work, what I mean is I opened System Monitor and it showed (and shows) only 4 GB.
But the things is, some programs/utils cat detect it here I will paste all the output of the commands I've tried
inxi -Fxz
System: Host: lmde Kernel: 4.8.0-53-generic x86_64 (64 bit gcc: 5.4.0)
Desktop: Cinnamon 3.4.3 (Gtk 3.18.9-1ubuntu3.3) Distro: Linux Mint 18.2 Sonya
Machine: System: LENOVO product: 20250 v: Lenovo Z710
Mobo: LENOVO model: Durian 7A1 v: 31900004Std Bios: LENOVO v: 7FCN35WW date: 09/02/2013
CPU: Quad core Intel Core i7-4700MQ (-HT-MCP-) cache: 6144 KB
flags: (lm nx sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx) bmips: 19156
clock speeds: max: 2400 MHz 1: 2400 MHz 2: 2147 MHz 3: 2350 MHz 4: 2400 MHz 5: 2400 MHz 6: 2400 MHz
7: 2399 MHz 8: 2400 MHz
Graphics: Card-1: Intel 4th Gen Core Processor Integrated Graphics Controller bus-ID: 00:02.0
Card-2: NVIDIA GK107M [GeForce GT 745M] bus-ID: 01:00.0
Display Server: X.Org 1.18.4 drivers: intel (unloaded: fbdev,vesa) FAILED: nouveau
Resolution: 1920x1080@60.02hz
GLX Renderer: Mesa DRI Intel Haswell Mobile GLX Version: 3.0 Mesa 12.0.6 Direct Rendering: Yes
Audio: Card-1 Intel 8 Series/C220 Series High Definition Audio Controller
driver: snd_hda_intel bus-ID: 00:1b.0
Card-2 Intel Xeon E3-1200 v3/4th Gen Core Processor HD Audio Controller
driver: snd_hda_intel bus-ID: 00:03.0
Sound: Advanced Linux Sound Architecture v: k4.8.0-53-generic
Network: Card-1: Intel Wireless 7260 driver: iwlwifi bus-ID: 07:00.0
IF: wlp7s0 state: up mac: <filter>
Card-2: Qualcomm Atheros QCA8171 Gigabit Ethernet driver: alx port: 3000 bus-ID: 08:00.0
IF: enp8s0 state: down mac: <filter>
Drives: HDD Total Size: 1240.3GB (6.3% used) ID-1: /dev/sda model: ST1000LM014 size: 1000.2GB
ID-2: /dev/sdd model: ADATA_SP580 size: 240.1GB
Partition: ID-1: / size: 220G used: 20G (10%) fs: ext4 dev: /dev/sdd2
RAID: No RAID devices: /proc/mdstat, md_mod kernel module present
Sensors: System Temperatures: cpu: 59.0C mobo: 59.0C gpu: 45.0
Fan Speeds (in rpm): cpu: N/A
Info: Processes: 294 Uptime: 1:24 Memory: 2301.1/3863.2MB Init: systemd runlevel: 5 Gcc sys: 5.4.0
Client: Shell (zsh 5.1.1) inxi: 2.2.35
sudo lshw -short -C memory (pasting with sudo so others cat just copy-paste)
H/W path Device Class Description
============================================================
/0/0 memory 128KiB BIOS
/0/4/b memory 32KiB L1 cache
/0/4/c memory 256KiB L2 cache
/0/4/d memory 6MiB L3 cache
/0/a memory 32KiB L1 cache
/0/2a memory 20GiB System Memory
/0/2a/0 memory 16GiB SODIMM DDR3 Synchronous 1600 MHz (0,6 ns)
/0/2a/1 memory DIMM [empty]
/0/2a/2 memory 4GiB SODIMM DDR3 Synchronous 1600 MHz (0,6 ns)
/0/2a/3 memory DIMM [empty]
sudo lshw -class memory
*-firmware
description: BIOS
vendor: LENOVO
physical id: 0
version: 7FCN35WW
date: 09/02/2013
size: 128KiB
capacity: 4032KiB
capabilities: pci upgrade shadowing cdboot bootselect edd int13floppynec int13floppytoshiba int13floppy360 int13floppy1200 int13floppy720 int13floppy2880 int9keyboard int10video acpi usb biosbootspecification uefi
*-cache:0
description: L1 cache
physical id: b
slot: L1 Cache
size: 32KiB
capacity: 32KiB
capabilities: synchronous internal write-back instruction
*-cache:0
description: L1 cache
physical id: b
slot: L1 Cache
size: 32KiB
capacity: 32KiB
capabilities: synchronous internal write-back instruction
configuration: level=1
*-cache:1
description: L2 cache
physical id: c
slot: L2 Cache
size: 256KiB
capacity: 256KiB
capabilities: synchronous internal write-back unified
configuration: level=2
*-cache:2
description: L3 cache
physical id: d
slot: L3 Cache
size: 6MiB
capacity: 6MiB
capabilities: synchronous internal write-back unified
configuration: level=3
*-cache
description: L1 cache
physical id: a
slot: L1 Cache
size: 32KiB
capacity: 32KiB
capabilities: synchronous internal write-back data
configuration: level=1
*-memory
description: System Memory
physical id: 2a
slot: System board or motherboard
size: 20GiB
*-bank:0
description: SODIMM DDR3 Synchronous 1600 MHz (0,6 ns)
product: CT204864BF160B.C16
vendor: Unknown
physical id: 0
serial: A4205EAD
slot: DIMM0
size: 16GiB
width: 64 bits
clock: 1600MHz (0.6ns)
*-bank:1
description: DIMM [empty]
product: Empty
vendor: Empty
physical id: 1
serial: Empty
slot: DIMM1
*-bank:2
description: SODIMM DDR3 Synchronous 1600 MHz (0,6 ns)
product: M471B5173BH0-YK0
vendor: Samsung
physical id: 2
serial: 136B8093
slot: DIMM2
size: 4GiB
width: 64 bits
clock: 1600MHz (0.6ns)
*-bank:3
description: DIMM [empty]
product: Empty
vendor: Empty
physical id: 3
serial: Empty
slot: DIMM3
sudo dmidecode
free -m
total used free shared buff/cache available
Mem: 3863 2406 277 430 1178 696
Swap: 0 0 0
cat /proc/cmdline
BOOT_IMAGE=/boot/vmlinuz-4.8.0-53-generic root=UUID=91af3ab8-8c93-40ef-930a-2dc7038f2dfc ro elevator=deadline quiet splash vt.handoff=7
dmesg | grep -i memory
did but it's very long
Also:
-I booted to BIOS and it showed that there is 20 GB (but it said in MB, something like 20480 MB)
-I visited Intel page for my processor(google for Intel® Core™ i7-4700MQ Processor can't paste links, have newbie restrictions) for my CPU and it said that it does support 32 GB
-I booted to Windows 10 live CD and it show that it has 20 GB but only 4 GB is available
-I did memtest86 here are the screenshot with results
what I don't like about it is that in the top left corner it shows that [c]Memory: 4009 MB[/c]. So was the 16 GB detected?
-I booted to Linux Mint live CD and it showed exactly the same as current version (4 GB).
-I found on internet that it can be caused by that contacts on the module was made "dirty" with dirt on my hands, so plugged it out got, wipe with ethanol, I did that but not with ethanol, instead of it I used vodka same results didn't work.
-I swapped RAM modules, didn't work.
I don't remember exactly, but also with installation the GRUB menu broke, what I mean is I got black screen for 3 seconds (which I can configure from /etc/default/grub).
The only thing where I kind of "broke the rule" is before buying it, I visited (google for Lenovo Lenovo Z710 compatible upgrades crucial) crucial website for my laptop (they have very fluent interface to choose the upgrades) and it says that the max RAM is 16 GB (8 + 8 ), I've ignored it.
[update]
Antz answer kind of solves my problem, but the real answer with code example was given on official Linux Mint Forum. sudo dmidecode gave huge output, but there it said about error that I had
Handle 0x0005, DMI type 5, 24 bytes
Memory Controller Information
Error Detecting Method: None
Error Correcting Capabilities:
None
Supported Interleave: One-way Interleave
Current Interleave: One-way Interleave
Maximum Memory Module Size: 8192 MB
Best Answer
In summary, one of two things generally happens. The memory works, but is limited to the maximum amount supported by the motherboard, or the memory doesn't work at all.
Let me be a bit detail to you.
On every motherboard, there is a controller for accessing the RAM. The limiting factor is how much memory can be accessed (or addressed) by that memory controller. Theoretically, a 64-bit CPU can access 2^64 bytes of RAM. For practical reasons, however, the number of addresses lines actually etched into a motherboard is much smaller, and the controller is created to be able to access up to a specific number of addresses. It can address fewer memory locations just fine as well. That determines the range and maximum amount of memory.
So when memory is installed with more addressable bytes than the controller understands, the best outcome is that only the lower portion of the RAM is used. However, because of the way memory is constructed, it's also possible that the larger memory won't work at all as that's the case with yours.
But again, it depends on the motherboard on how it handles memory errors.
This stackexchange site gives more detailed information concerning your RAM issue. What happens when more RAM is installed than the motherboard supports?
You can also read this: RAM.