RAM upgrade info for early-2008 MBP is incorrect

I agree there is conflicting info in two different parts of that article. Any Late 2007/Early 2008 MBP should have a max RAM (officially) of 4GB (2 X2GB). Unofficially, they should be able to handle a total of 6GB with one 2GB and one 4GB using modern modules that post-date Apple's original specs (that seldon get updated when new compatible RAM appears). However, installing 2 X 4GB will cause a boot failure.

First, let's make sure we have your exact model pinned down. Do "About this Mac" from the Apple menu and, in the resulting screen, click the "More info..." button. That launches System Profiler which wil be showing its "Hardware Overview" screen:

The data that is the key is the second line, "Model Identifier" in OS10.5 and higher. Please post the code in that line.

Beyond that, I believe hat your symptoms sound like incompatible RAM. Some RAM that is fine for a PC may not work properly in a Mac. Example: when the pre-Unibody MBPs were hot stuff, there were a number of reports around here about Kingston RAM. Their "Value-line" RAM would not work in MBPs but their more expensive main product line RAM would.

I'm having the same exact issue with my Early 2008 MBP, I bought a Centon 2x2GB kit and I can only use one 2GB and one 1GB, I can't use both for a total of 4GB, is there any resolution here? Also, I've tested that both of the 2GB modules work by testing each with one of the stock 1GB modules.

This is why you will usually see the most experienced participants in these forums recommend buying RAM only from vendors who cater specifically to Mac users and have tested what they sell in Macs. Centon RAM may be fine in PCs, but it's practically never mentioned in these forums, and I've never seen anyone recommend it for use in a MBP.

Yeah, initially I had purchased some PNY memory that simply had a "Mac compatible" insignia printed on the package. I had the same problem with that memory that I'm having with the Centon. Funny enough, I purchased the Centon from Microcenter, from their Mac-specific section, and the memory itself is packaged as Mac-specific memory and everything. Same problems. What I'm wondering is this, is it possible that my MacBook Pro is only capable of holding upto 3GB? There's a small section of the MacBook Pro memory install KB on Apple's support site that mentions that a 15-inch and 17-inch Core 2 Duo MacBook Pro

Down at the bottom of this screen shot, there's a section that says exactly what I mentioned before. But below that, the page mentions that the MacBook Pro 15-inch Early 2008 (which is exactly what my System Profiler tells me my laptop is) is capable of holding 4GB. I don't mind if my actual max is 3GB I just want to know for sure if it's the memory (twice) or a limitation of my system. Thanks for your input! 🙂

Hi: too have an early 2008 macbook pro and at some time apple fixed the 4mb topend that my beast had. I installed 8mb from OWC just last week, and it is working fine. My macbookpro is the 2.53 mh model that had numerous small problems (black flashing lines when using the low end graphics card, etc.) and Apple has fixed all the problems over time. And that is why I'll be an Apple user for life. Aaron

aaronhd33s@hotmail.com

It's the RAM, not a system limitation. Your machine can use 4GB (two suitable 2GB modules) or 6GB (one 2GB and one 4GB suitable module) but not 8GB — the "Additional Notes" box in your screenshot above contains a mistake, which has been pointed out to Apple several times through the hosts of these discussions, but has not yet been corrected.

Apple supports up to 4GB in that model, as the bottom box in your screenshot correctly indicates. Apple does not support installing 6GB, but 6GB has been extensively tested and found to work well in it by OWC, a highly reliable vendor of Mac RAM.

http://eshop.macsales.com/shop/memory/MacBook/Pro/Core2/

Apple has contributed hugely to the widespread confusion about this, not just through the error captured in your screenshot, but even more significantly through product naming practices that have long been extremely unclear and unhelpful — and now, as I gather, by providing only those useless product names in Lion's System Report instead of the Model Identifiers that used to be shown there. If I am wrong and System Report in Lion still does show the Model Identifier, then I withdraw the accusation. I don't have Lion, so I can't check and see.

Aaron: If your MBP has two GPUs, it isn't an early-2008 model. It's the late-2008 unibody model, introduced in October of that year, and it can indeed use 8GB of RAM. I have the 2.4GHz version of the same model, also with 8GB of OWC RAM installed.

eww wrote:

If I am wrong and System Report in Lion still does show the Model Identifier

It does.

Good! Thanks for clearing that up for me.

Hi: yes I misspoke earlier I do have the late 2008 macbookpro, sorry for the confusion on my part. Aaron

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Eww: Thanks for your help! I returned the Centon brand 2x2GB and bought two 2GB chips from Crucial and they worked right away. It's hard to believe that someone can buy two lemons in a row but that's exactly what happened to me. Funny thing is that the two previous vendors, PNY then Centon, were each more expensive than the Crucial brand that actually works, with the PNY being the most expensive and the Centon coming in just under that.

At any rate, I'll be shopping for a 4GB DDR from Crucial in the near future so I can really max out my MBP. Thanks again 🙂