I have a Aluminium Late 2008, and i want to know if a 1333 RAM works

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It won't work. Your Mac needs PC3-8500 1066 MHz DDR3 RAM, and if you install a different type of memory, your Mac may not start up because it's not the correct memory.

You can buy more RAM at OWC or Crucial. See > http://support.apple.com/kb/HT1651#link2

You are welcome

Hi,

I replaced yesterday RAM memory on my unibody aluminium MacBook (late 2008, ver. 5,1). It runs OS X 10.9.1 (13B42) on boot ROM version MB51.007D.B03.

It had 2 x 1 GB at 1066 MHz and I ugraded it to 2 x 2 GB at 1333 MHz. The "new" RAM memory is Hynix, taken from a 2011 iMac.

It works perfectly, I have no problem even with apps other users reported as crashing after update (e.g. Google Earth).

The only concern - and this is a major one, that might prompt me to return to the original 2 x 1 GB 1066 MHz - is power use. After upgrade my MacBook seems to consume battery roughly twice as fast as before.

A previous discussion in where this came up, the stated answer was these were interchangable, was questioned by me; in that the iMac did not require the low-power RAM to function, but the portable did for most power-efficiency; and the parties to that specific discussion (ASC) did not bring up or recognize the point.

Also there is a matter of greater heat generation due to the power consumption, so that could shorten the life of the portable computer should it be running the less power-efficient hotter RAM. While the pin placement & count in one series will physically fit the other and boot it, there are differences worth considering. Important enough ones.

Some things to consider, at least you are aware of them...

Good luck & happy computing! 🙂