Putting memory chips from Macbook Pro into white Macbook

[PenguinApple]

Last week I upgraded the memory of my Macbook Pro (2011 edition) to 8GB replacing both 2GB chips by 4GB chips, so the old 4GB chips became obsolete.

My girlfriend has a 2009 white Macbook with 2 GB in it and I'd like to replace that 2 by my old 4GB.
The chips of the MBP are 1333MHz while the Macbook bus speed is 1066MHz so that can't be a problem as the chips are not slower than the bus speed.

What are your opinions ?

 

[The-Pro]

Which 2009 MacBook is it? Is it the unibody polycarbonate one or the older one?
I ask this because the old one used DDR2 RAM while the unibody one used DDR3 RAM.

If the RAM which is installed is DDR2 then the RAM from your MBP will not work in it, if the RAM installed is DDR3 then the RAM from your MBP will work, but at 1066MHz instead of 1333. The difference between 1066 and 1333 wont be noticeable.

 

[PenguinApple]

Thanks.

It is DDR3 memory so that is not the problem. But do you mean it will runs alower ? The bus speed is 1066MHz and the original chips are also 1066, so the new 1333 will also run on 1066, so this appears to me it will run at the same speed as the old chips. Or am I wrong ?

 

[The-Pro]

yes it will run at the same speed as the old chips just not at the maximum speed, 1333.