Upgrade RAM: Linux says it admits 32 GB but manual says 16 GB

[Alday]

Hello,

I want to upgrade the memory of my laptop (HP 250 G5 W4Q07EA I5-6200U/8GB/256GB SSD/15.6), I was thinking on adding a 16 GB stick the 8 GB stick that came with the laptop. I use Linux as OS, and it says that the laptop can handle up to 32 GB of RAM. 

# dmidecode 3.1
Getting SMBIOS data from sysfs.
SMBIOS 2.8 present.

Handle 0x0028, DMI type 16, 23 bytes
Physical Memory Array
	Location: System Board Or Motherboard
	Use: System Memory
	Error Correction Type: None
	Maximum Capacity: 32 GB
	Error Information Handle: No Error
	Number Of Devices: 2

After searching a bit to know if I could fit a 16 GB  along with the 8 GB stick, because I didn't know if it was single channel or dual channel, and even if it was dual channel if it could work with both in single channel,  I found that the manual says you can only fit up to 16 GB. (Post 1, Post 2...)

If I have to chose between what Linux says and what HP says, I would stick with HP, but I'm my opinion Linux development has grown and improved a lot since the beginning and It's hard to believe it's displaying the information wrong. Could it be that the hardware allows up to 32 GB but is somehow restricted by the bios or something else? 

[Lil_Boy_Blue]

Hi

https://support.hp.com/us-en/product/hp-250-g5-notebook-pc/10180321/document/c05078579

DDR4 (Intel Core i7-6500U. i5-6200U, i3-6100U processors only)

DDR4-2133 (transfer rates up to 2133 MT/s) One SODIMM slot Dual channel support Non customer accessible / upgradeable Maximum: Up to 16 GB Configuration 4096 MB Total System Memory (2048 MB x 2) 4096 MB Total System Memory (4096 MB x 1) 6144 MB Total System Memory (2048 MB x 1 + 4096 MB x 1) 8192 MB Total System Memory (4096 MB x 2) 8192 MB Total System Memory (8192 MB x 1) 12288 MB Total System Memory (8192 MB x1 + 4096 MB x 1) 16384 MB Total System Memory (8192 MB x 2)

DDR3L (Intel CoreTM i3-5005U processor only)

DDR3L – 1600 (Transfer rates up to 1600 MT/s) Dual channel support Non customer accessible / upgradeable Maximum: Up to 16 GB

So it should be obvious when you inspect it, only one slot.

[Alday]

Thank you for you answer Lil_Boy_Blue.

I think what the documentation wants to say is  that there is 1 slot available as 1 is already taken from the RAM the laptop comes with. In the combinations below, it shows combinations for two slot.

Also, a lot of dissasemblies show that there are 2 slots https://youtu.be/QbVveeWKq9c?t=373 https://youtu.be/w2TeVC-9soU?t=217

[pepe999 · Accepted solution]

Hi,

The Maintenance and Service guide provides you the information based on what the system was TESTED. It says 16GB because they tested it with 16GB (2x8GB) of RAM before the computer was on sale. At the time the 8GB memory modules were the standard. Intel mobile 2nd Gen Sandy Bridge processors support 32GB of RAM natively so there is a huge chance that 32GB of RAM will work on Haswell (4th) and higher architectures. 

I see the laptop has a solid state drive and comes already with 8GB of RAM. 8GB of RAM is a lot of memory for a linux machine and 16GB would be more than enough. If you consider the cost of a 16GB memory stick you get very little upgrade for getting 2x 16GB to 1x 8GB module to work with the existing 8GB one in dual channel if 2 slots are available. 

There used to be some hardware restrictions (hard drive, wifi, etc) but I believe it's all gone. Last laptops with these restrictions were the Sandy Bridge Envy Pavilion dv6 or dv7 6000 models.

[Alday]

Thank you for the answer.

I finally bought a 16 Gb stick to have more room to run virtual machines and make it more future-proof, and everything seemed OK and the beginning, but the hdmi port was not working, and I could not write to any SD card, not matter what, even changing the ownership...

I switched the 16 Gb and 8 Gb stick and now everything is working properly. Just in case I download memtest to an bootable USB and passed the default scan (about 8 hours), and did not find any issue (tough is does not mean there are not issues or incompatibilities). 

I also used stress tool to fill 80% of the RAM available and used it normally to see if there was any issue, and didn't have any, at least that I could notice.

If it is of help to anybody, the final config is:

# dmidecode 3.1
Getting SMBIOS data from sysfs.
SMBIOS 2.8 present.

Handle 0x0028, DMI type 16, 23 bytes
Physical Memory Array
	Location: System Board Or Motherboard
	Use: System Memory
	Error Correction Type: None
	Maximum Capacity: 32 GB
	Error Information Handle: No Error
	Number Of Devices: 2

Handle 0x0029, DMI type 17, 40 bytes
Memory Device
	Array Handle: 0x0028
	Error Information Handle: No Error
	Total Width: 64 bits
	Data Width: 64 bits
	Size: 16384 MB
	Form Factor: SODIMM
	Set: None
	Locator: Bottom-slot 1(top)
	Bank Locator: BANK 0
	Type: DDR4
	Type Detail: Synchronous
	Speed: 2133 MT/s
	Manufacturer: 1315
	Serial Number: 22200519
	Asset Tag: 9876543210
	Part Number: CT16G4SFD824A.C16FDD
	Rank: 2
	Configured Clock Speed: 2133 MT/s
	Minimum Voltage: 1.25 V
	Maximum Voltage: 1.5 V
	Configured Voltage: 1.2 V

Handle 0x002A, DMI type 17, 40 bytes
Memory Device
	Array Handle: 0x0028
	Error Information Handle: No Error
	Total Width: 64 bits
	Data Width: 64 bits
	Size: 8192 MB
	Form Factor: SODIMM
	Set: None
	Locator: Bottom-slot 2(under)
	Bank Locator: BANK 2
	Type: DDR4
	Type Detail: Synchronous
	Speed: 2133 MT/s
	Manufacturer: Samsung
	Serial Number: 24213121
	Asset Tag: 9876543210
	Part Number: M471A1K43CB1-CRC    
	Rank: 1
	Configured Clock Speed: 2133 MT/s
	Minimum Voltage: 1.25 V
	Maximum Voltage: 1.5 V
	Configured Voltage: 1.2 V

[pepe999]

There could be some compatibility issues when the sticks are from different manufacturers. Swapping them was a smart idea. It was like a memory reset.