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StarStrike

macrumors member
Original poster
Dec 27, 2008
31
5
Hey guys,

I'm not sure if this question has been asked before (if it has I'm sorry), but I was wondering if my iMac (2010) is compatible with the ram from my MacBook Pro (Mid 2009).

I've recently purchased 2 4gb sticks of DDR3 1066mhz to upgrade my laptop to 8gb and wanted to add the 2 2gb sticks from my MBP to my iMac, however, I notice that the RAM modules run at different frequencies (i.e. my MBP is DDR3 1066mhz whereas the ram already in the iMac is DDR3 1333mhz).

Can I add the RAM from my MBP to the iMac or will it not work?
 
Are you sure? I thought iMacs and MBPs both use SO-DIMM sized memory sticks :confused:
 
It *should* work, but the 1333 MHz sticks will be clocked down to 1066 MHz. They both use SODIMM. If you're running out of RAM, then the performance increase of the additional RAM will far outweigh the difference between 1333 MHz and 1066 MHz, which won't even be noticeable.
 
Hmms, I thought so too, though does anybody know for sure? I know older computers have had their mobos fry when putting in incompatible RAM - lol I don't want that to happen here!

Thanks for your help so far everyone!

StarStrike
 
Later this afternoon I'll be doing just the opposite. Taking RAM from an iMac and putting it into a MacBook. If it works, or not, I'll post back.
 
The operation was a success.

I took 4GB of 800MHz RAM from my iMac 8,1 and installed it into a white MacBook 2,1 and it works just fine. The only catch is that 1. the bus speed was reduced to 667MHz to match the logic board bus speed and 2. the OS only recognizes 3GB of the 4GB installed due to the chipset of the time (same thing happened to my MBP 2,2).

Both points I expected to happen and they did. Otherwise, it works just fine. I also installed 10.6.6 combo update for my girlfriend too and that went off without a hitch.
 
OP, it works just fine. I did the exact same thing when I bought my iMac last month. The only thing is that all the ram is now listed as 1067. I've had no problems at all. The two 1gb sticks are from my macbook pro 2009.
 

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Thanks for the replies!

Just to clarify, if I'm putting the ram from my mid-2009 MBP into a 2010 iMac it will work, but the RAM will just be clocked at 1066mhz? (the original iMac ram I think is 1333mhz, but the MBP is 1066mhz)

I've called two Apple Stores around my area and I've been getting mixed responses - one said it definitely won't work and the other store said it *should* work :confused:

StarStrike
 
Thanks for the replies!

Just to clarify, if I'm putting the ram from my mid-2009 MBP into a 2010 iMac it will work, but the RAM will just be clocked at 1066mhz? (the original iMac ram I think is 1333mhz, but the MBP is 1066mhz)

I've called two Apple Stores around my area and I've been getting mixed responses - one said it definitely won't work and the other store said it *should* work :confused:

StarStrike

I stick with the "it should work" mantra. If the RAM is clocked at 1066MHz that is as fast as it will run. Just make sure the pin-out is the same, you don't want to force in a RAM stick that physically won't fit. The logic board of the computer will slow down to meet that speed. Go ahead and try it. The worst that can happen is the Mac won't start up. If that happens, put the original RAM back in and carry on as usual.
 
Thanks for the replies!

Just to clarify, if I'm putting the ram from my mid-2009 MBP into a 2010 iMac it will work, but the RAM will just be clocked at 1066mhz? (the original iMac ram I think is 1333mhz, but the MBP is 1066mhz)

I've called two Apple Stores around my area and I've been getting mixed responses - one said it definitely won't work and the other store said it *should* work :confused:

StarStrike

It works just fine. Look at my screenshot above. I know that it's hard to listen to folks on the internet, but look at the facts.

iMac 2010- ddr3 ram
mbp mid 2009- ddr3 ram

It's the same type of memory, just at a different clock speed.

The pins are all the same. Everything lines up properly.

Don't sweat it.
 
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