ThinkPad X201 Ram

[knotty robin]

no I mean the exact spec of the ram sticks

[cunning birch]

ahhh, haven't checked that yet, lemme see what info I can find

[knotty robin]

according to the internet, the only i5s that shipped with the x201 are 520um, 560um and 560m

and all of those only support dd3 according to intel

[cunning birch]

so the stick im trying to put in apparently PC3L

[cunning birch]

ah, so that wont work then cuz PC3L isnt the same as DDR3L ?

[knotty robin]

no
pc3 = ddr3
pc3l = ddr3l

and those processors cant cope with the L variant

can you share what ram sticks you have? some are supposed to be dual voltage

[cunning birch]

ohh wait, so these processors use the what's commonly referred as regular or desktop or am I completly off-track here ?

[knotty robin]

and on your thinkpad, if you take a close look at the plastic of the ram slot, it often says what type of ram it supports

[cunning birch]

the one's I want to put in or the ones in there right now ?

alr, lemme check

[knotty robin]

the distinction between desktop and laptop ram is DIMM or SO-DIMM

DIMM = dual inline memory module (inline means straight row of contacts and dual means on both sides)

SO = small outline

laptops use the small stuff

[cunning birch]

this is the one I want to put in, other one is basicly identical

[knotty robin]

ah yeah that last picture says "PC3L"

[cunning birch]

wow, I always thought that was basicly the only distinction there was

[knotty robin]

me too until i bought some ram for an old laptop

[cunning birch]

oof

but so is the thinkpad the more unusual one or the ram ?

like, what's more common ?

[knotty robin]

hard to say
but i think the thinkpad (or more exactly the first gen core cpu) is more unusual

but then again, some ram can do both voltages (idk how common that is though)

[cunning birch]

mhm, welp, guess I'm left with RAM I can't use and stuck with 4 gigs of ram on my thinkpad

wait, I got one more question, so the thinkpad is rated for max 8gigs, does that mean both 1x8 or only 2x4 ?

[knotty robin]

that is a really good question

[cunning birch]

mhm, good question but I just realized the answer wont save me either because the 8gig stick I bought is also PC3L

[knotty robin]

well maybe it is compatible

[cunning birch]

1.35V, first ram stick I see that actually says voltage

[cunning birch]

lemme try that

[knotty robin]

https://www.amazon.de/dp/B08J3NGCMH
i bought that and on the label it says PC3L and 1.35v but the description says that it is compatible with both

[cunning birch]

mh, that was one of the offerings I saw but I didnt read the description as I thought it didn't really matter

Gotta say tho, I find itvery interesting that it does get displayed correctly in the BIOS. Wouldn't have expected the BIOS to list it if it's the wrong voltage

[cunning birch]

tested it, unfortunately isn't

[knotty robin]

:c

[cunning birch]

that's a big F

but at least I learned something ;-;

[knotty robin]

I am honestly a bit confused too
this is the datasheet for that ram (M471B5173QH0)
https://download.semiconductor.samsung.com/resources/data-sheet/135V_DDR3_4Gb_Qdie_UnbufferedSODIMM_Rev121.pdf

and it has 1.35 volt right here

but they mention this in "key features"

[cunning birch]

mhh, that's odd

Maybe it isn't a voltage problem after all ? I just don't know how to check if it's a voltage problem or if it could be something else

[knotty robin]

but the thinkpad runs if you put the stock ram in it and that stock ram runs on other machines fine

[cunning birch]

haven't tried the stock ram on other laptops yet, could try that

[knotty robin]

really really strange
but i guess the ram just isnt 1.5v compatible
or maybe the voltage dips during startup and the ram goes into some kind of 1.35v mode or something
but thats just speculation

[cunning birch]

only ever tried the other way

let me the the other direction, brb

[knotty robin]

I'm afk now (dinner)

[cunning birch]

k

Welp, I made an interesting discovery: the other laptop didn't even want to boot with even only one thinkpad ram module. Considering the fact I have 3 Laptops and 3 sets of ram total involved here it seems like the X201 is the oddball

[knotty robin]

yeah
and i found some closure in the datasheet

if i look up the old thinkpad ram i get this "IDD Spec table"

but the table for the 4g sticks only shows ddr3l

but all in all it is still super strange that grub loaded and worked but no os did

[cunning birch]

yeah and as I said, would expect the BIOS to just not show the RAM at all but oh well

[knotty robin]

i would expect that communication to be in some super slow compatible protocol that barely manages to make it work

[cunning birch]

mhm, welp, guess I'm stuck without a slow protocol but therefore only 4gb, another arch installation onto that new ssd it is then

And thank you very much for explaining the RAM types, seriously did not know there was so much to look at before buying RAM; good to know for the next time I try to buy RAM for a thinkpad ;-;

[knotty robin]

np and have fun with arch (btw) 😊

[cunning birch]

ty 😄