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My Mac (Mid 2009- MacBookPro5,5) laptop installing OS 10.8.2.

Currently, it is using 2 x 1GB (1066 Mhz).

My friend gave me 2 x 2GB (1600 Mhz) of his 2012 Mac.

After installing 2 x 2GB (1600 Mhz) on my Mac, it can not boot but can not start OS. This is the error that show on boot start up screen:

enter image description here

But it is possible to install 1x 1GB (1066) + 1x 2GB (1600). The system can down-clock it to both 1066 Mhz. But what i still have 1 x 1GB (1066) + 1x 2GB (1600) left!

3GB @ 1066 Mhz

My question is: Any better solution than using 1x 1GB (1066) + 1x 2GB (1600)?

More certainly, is there any way to install 2 x 1600 Mhz? (even down-clocking to 1066 is accepted). (currently, 2x1600 Mhz can not startup OS).

Edit 1: 4 RAM are healthy.

share|improve this question
Yep. A faster ram is always capable to speed down to lower frequences ... – Matthieu Riegler Jan 31 '13 at 0:50
@MatthieuRiegler: My question is: how to do it. I am very appreciate the answer about how to down-clock 2x1600 to 1066 on this system? Because currently, i can not start my system with 2x2GB. – BachT Jan 31 '13 at 6:53
It should do it automaticaly. It's not the ram it self who desides at which speed it runs. – Matthieu Riegler Jan 31 '13 at 10:44
I've posted an answer that is incorrect. But it should do it automatically, if not, it's problem with the module. – Shane Hsu Jan 31 '13 at 11:25

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