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Late 2008 MBP RAM upgrade help

C

carlsbergbeer

macrumors member
Original poster
Feb 28, 2005
31
6
I'm trying to upgrade my RAM from 4gb to 8gb.
I have the appropriate 4gb Crucial chips from Amazon.
Here is the problem:
When I install both new chips, it only recognizes slot "DIMM0"
DIMM1 shows up as empty.
I tried leaving the new 4gb chip in DIMM1 and putting an old 2gb chip in DIMM0.
It then recognized still only DIMM0, for 2gb.
Worried that I somehow broke DIMM1 while upgrading, I put both old 2gb chips back in.
It recognized both slots!
I have the current firmware and SMC versions. I'm running 10.10.5.
I searched through a bunch of articles and I can't understand why it isn't recognizing 8gb.
Any ideas?
Thanks
 
Please provide a little more information. :D
What screen size and is it an early or late 2008 MBP? Exactly what are the specifications for the RAM you purchased?
 
carlsbergbeer said:
I'm trying to upgrade my RAM from 4gb to 8gb.
I have the appropriate 4gb Crucial chips from Amazon.
Here is the problem:
When I install both new chips, it only recognizes slot "DIMM0"
DIMM1 shows up as empty.
I tried leaving the new 4gb chip in DIMM1 and putting an old 2gb chip in DIMM0.
It then recognized still only DIMM0, for 2gb.
Worried that I somehow broke DIMM1 while upgrading, I put both old 2gb chips back in.
It recognized both slots!
I have the current firmware and SMC versions. I'm running 10.10.5.
I searched through a bunch of articles and I can't understand why it isn't recognizing 8gb.
Any ideas?
Thanks
Click to expand...


It sounds like you cought the wrong spec RAM, also the 2008 has a max RAM amount of 6GB.
 
Thanks for the replies.
It is a late 2008 MBP unibody 15" with 2.4ghz processor.
The RAM I bought is crucial 1067 DDR3.
Pretty sure it is the right RAM.

I tried again to put both new chips in and it only recognized 1 slot.

I then put both old chips back in and it recognizes both slots.

Everything I've read says that I should be able to run 8gb.

Thanks
 
carlsbergbeer said:
Thanks for the replies.
It is a late 2008 MBP unibody 15" with 2.4ghz processor.
The RAM I bought is crucial 1067 DDR3.
Pretty sure it is the right RAM.

I tried again to put both new chips in and it only recognized 1 slot.

I then put both old chips back in and it recognizes both slots.

Everything I've read says that I should be able to run 8gb.

Thanks
Click to expand...
8GB Kit (4GBx2) DDR3 PC3-8500 Unbuffered NON-ECC 1.5V 512Meg x 64
CT3631182
  • DDR3 PC3-8500 • CL=7 • Unbuffered • NON-ECC • DDR3-1066 • 1.5V • 512Meg x 64
Is that what you ordered?
 
carlsbergbeer said:
Thanks for the replies.
It is a late 2008 MBP unibody 15" with 2.4ghz processor.
The RAM I bought is crucial 1067 DDR3.
Pretty sure it is the right RAM.

I tried again to put both new chips in and it only recognized 1 slot.

I then put both old chips back in and it recognizes both slots.

Everything I've read says that I should be able to run 8gb.

Thanks
Click to expand...

Take a look at Gav2K's post above it seems you need an EFI update, I was just going off of crucials upgrade website which states 6GB only for the 2008.

http://blog.macsales.com/9102-secret-firmware-lets-late-08-macbooks-use-8gb

As to the RAM sounds fine to me, could it be a faulty new RAM chip??
 
This is what I ordered:
http://www.amazon.com/gp/product/B008LTBJFM?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00

It seems as if my computer is not accepting 8gbs. I tried both new 4gb chip in DIMM1, and it did not recognize either, however it does recognize the old 2gb chips.

I was under the impression that my boot ROM version is current. But is .... BO5 newer than B06?

I recently upgraded to a 500gb SSD with a clean install of 10.10.5

Model Identifier: MacBookPro5,1
Boot ROM Version: MBP51.007E.B06
SMC Version (system): 1.33f8
 
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carlsbergbeer said:
Weird. Maybe later I'll try one more swap. If that doesn't work I'll send this RAM back to Amazon and live with 4gb.
Click to expand...
Chances are the ram is faulty as there is no reason it wouldn't work. Also if your in the uk order direct from crucial as your paying way over the top for that ram. It's listed as £43.19
 
Also I just noticed there is a discrepancy between crucial.com and .co.uk

.com lists as 1.35v
.co.uk lists as 1.5v

Check what your current ram is spec'd at
 
I agree, everything looks good. Your MBP should support 8 Gb of RAM as confirmed at:
http://www.everymac.com/systems/app...-2.4-aluminum-15-late-2008-unibody-specs.html
From everymac:
RAM Type: PC3-8500 DDR3 Min. RAM Speed: 1066 MHz
*Apple officially supports a maximum of 4 GB of RAM. Originally, this model was only unofficially capable of stably supporting 6 GB of RAM, but as confirmed by site sponsor OWC, it is capable of supporting 8 GB of RAM if updated to Boot ROM Version MBP51.007E.B05 and running MacOS X 10.6 "Snow Leopard" or higher.

See the OWC (macsales) blog article:
http://blog.macsales.com/9102-secret-firmware-lets-late-08-macbooks-use-8gb
According to it B06 should also allow 8 Gb (it did not disable the 8 Gb allowed in B05). It does have links to the firmware update. Also, according to the article there was a "secret" update.

Maybe see if you to apply the Boot ROM B05 (MacBook Pro EFI Firmware Update 1.8) again? I'll admit I'm not sure if it is ok to do B05 since you already have B06. Maybe some other members can comment.
https://support.apple.com/kb/DL975?locale=en_US
 
@CoastalOR Thanks- good info.
I'll also check crucial's website for an exact spec. @Gav2k

Thinking it may have something to do with 1.5V vs 1.35V RAM.

For $50 the upgrade from 4-8gb is a no brainer. The computer is fast but when safari, music, photos, etc, etc, etc are running it can tax the RAM.

Thanks again.
 
Last edited:
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