Mid 2012 15" - Ram Problems: PC3L vs PC3

Question

Mid 2012 15" - Ram Problems: PC3L vs PC3

I can't find any solid information regarding the Mid 2012 15" Macbook Pro and it's memory fussiness.

All I find are people, and websites saying PC3L will be fine.

This is not the case for me.

Twice I have bought (fully tested and guaranteed) 2nd hand ram from CEX that turned out to be PC3L. My Mac won't start up. Upon return, they test the ram in a PC, and it works fine. Just not in my Mac.

Upon inspection my current Ram is PC3, and obviously works. My problem is CEX don't list online whether the Ram is PC3 or PC3L. So I have taken a gamble.

I wasn't aware of these two types until this evening, and thought the first purchase didn't work because the modules were from 2 vendors: Samsung and Kingston.

Earlier today I was in store and picked two identical Samsung modules, unfortunately before I was aware of the "L" difference. The mac did the horrid "don't like this Ram" beep.

I'll be returning the Ram for store credit (again!), but wanted to know why there is a plethora of misinformation regarding PC3L vs PC3, or if my machine is an isolated case that won't run PC3L?

MacBook Pro

Posted on Mar 5, 2019 10:52 AM

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Answer 1

leroydouglas

Level 10

200,250 points

Mar 5, 2019 12:30 PM in response to Richard Roberts1

Best to buy RAM from reliable source with the exact specs.

Usually a lifetime guarantee on RAM from third party source like:

https://eshop.macsales.com/shop/apple/memory/

Macsales/OWc has excellent technical support, if in doubt you can ask them

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Answer 2

Mar 5, 2019 1:31 PM in response to leroydouglas

Thanks for taking the time, but that doesn't answer my question. I never mentioned I'm in the UK, so unfortunately OWC is of no use to me.

Just to let you know I am fully aware that buying new from a company that lists the ram as compatible with said model is a guarantee that it will be the correct type. I have been using and installing ram on Macs since 1991,

My issue is wanting to learn the facts about PC3L vs PC3, and why some advice claims both will work, when my experience does not reflect that.

Buying new from Crucial, or other vendors is not what I have chosen to do due to budget restrictions, and it's an old mac.

CEX, like I mentioned fully guarantees their stock for 3 years, and the prices are great. I have bought ram from them for a previous Mac, and also sold them the ram from that Mac. I will endeavour to track down some PC3 through CEX, and make sure it isn't PC3L. But in the meantime I would like to find solid irrefutable facts on the usage (or incompatibility) of PC3L in a Mid 2012 MBP 15".

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Answer 3

Mar 6, 2019 2:39 AM in response to HWTech

Thanks HWTech, I really appreciate the level of detail you went into. It's a difficult subject to research.

Your experience with the generic Crucial being intermittent in your mac but fine in the pc, is just the info I needed. I wish these differences were noted by manufacturers, simply to help us understand the subtleties of their different products, and to pass on knowledge.

I will save myself the headache of hoping for the right stock to appear at CEX. I'll get some from Crucial, and pay more... even though I wanted to save money on this non critical Mac. I wouldn't have been so penny pinching if it was a mac essential to business needs.

I'll re-inspect the locking levers, they seemed ok, but this mac is a recent 2nd hand purchase (my only 2nd hand mac ever) and you never know what clumsy fingers have been in there.

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Answer 4

Mar 6, 2019 3:17 AM in response to babowa

I'd foolishly been using to Duck Duck Go to search the web regarding OWC shipping and had found nothing. After reading your post I Googled... and found the info on international shipping. Thank you.

The Google search also showed me that there are regional OWC outlets outside the US, that were not shown by Dumb Duck Go (nowhere). I guess it's back to being stalked by Google if I want good results.

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Answer 5

Mar 5, 2019 3:35 PM in response to Richard Roberts1

I have actually used the Crucial recommended DDR3L RAM in the Mid-2012 laptops without any issues.

Macs are very picky about the RAM they use. I once used Crucial RAM with the correct specifications, but it wasn't a part number Crucial used for Apple and the RAM had intermittent issues (the RAM was good & worked great in a non-Apple system). If I buy RAM from Crucial for a Mac, then I always use Crucial's tools to identify the correct part number and I've never had a problem again. If Apple is this picky, then good luck with anything but a name brand and the correct part for a Mac.

I will only ever use name brand RAM as anything else usually causes intermittent issues due to poor quality or being incompatible and I don't need the hassle. Trying to get bargain rates on RAM below the rates of name brands will always cause you problems like you are experiencing. The quality of the chips & supporting circuitry are always in question as those discount vendors cut corners somewhere to get those prices. Of course there will be times when it will work, but I for one want reliability.

FYI, When installing RAM in a Mid-2012 laptop, make sure both modules lock in place. Sometimes installing the second module will pull the locking lever apart enough to release the first module you installed. Also make sure the little triangular nubs on the locking levers are Ok as those triangular nubs can be damaged when inserting & removing RAM. If the nubs are worn, it may not sufficiently lock the memory in place.

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Answer 6

babowa

Level 9

78,574 points

Mar 5, 2019 3:55 PM in response to Richard Roberts1

FYI, OWC does send to countries other than the US and, although it may be an old computer, it is still a Mac and, therefore, very finicky about the RAM it demands. So, your decision - either go with Crucial or OWC or take a chance. Make sure the place offers a warranty and has a good return policy.

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Mid 2012 15" - Ram Problems: PC3L vs PC3

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