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firelighter487

macrumors 6502
Original poster
Apr 30, 2014
385
238
The Netherlands
i'm planning on buying a used macbook pro 13 inch late 2011, but have a question.

it's quite cheap because it has only 4GB of ram. now, i have ddr3 sodimm memory spare, but it's 1600mhz.
on apple's page it specifies that this model uses 1333 mhz memory.
will it work with my spare ram? just at lower clock speed? or will it not boot and would i have to get new memory for it?

thanks!
 

Macdctr

macrumors 65816
Nov 25, 2009
1,012
732
Ocean State
I wouldn't buy 1600MHz memory if you haven't purchased it yet. I doubt the 5,1 MacPro will boot with it installed...
 

MBP_187

macrumors regular
May 10, 2016
155
18
Dhaka, Bangladesh
i'm planning on buying a used macbook pro 13 inch late 2011, but have a question.

it's quite cheap because it has only 4GB of ram. now, i have ddr3 sodimm memory spare, but it's 1600mhz.
on apple's page it specifies that this model uses 1333 mhz memory.
will it work with my spare ram? just at lower clock speed? or will it not boot and would i have to get new memory for it?

thanks!

Hi,

Short answer : it works! I have done it myself.

Please read this Thread : https://forums.macrumors.com/threads/1333mhz-vs-1600mhz-ram.2063325/#post-24931571

Deals with exactly what you are asking. Good Luck.
 

Fishrrman

macrumors Penryn
Feb 20, 2009
28,984
13,036
You didn't ask this, but...
... I'd suggest buying at least a 2012 MBP instead.
It has USB3, which is a HUGE "jump up" over USB2.
 

Maxx Power

Cancelled
Apr 29, 2003
861
335
The second module should down-clock itself to match the slowest of the two. This should work in theory, but odd times you get incompatibility issues with the stick and the other stick, or the stick and the computer. It worked fine for my older Mac Mini with a stick of 1066 Mhz and a stick of 1600 Mhz, both run at the specifications of the 1066 Mhz (this is much more common in the PC world, if you Google around). If you look at any DDR3 SODIMM with a memory timing and frequency read-out tool (like CPU-Z in Windows), you'll see that as per JEDEC specifications, there are multiple speeds and timings that the stick will run at (which means that memory is generally backwards compatible on a frequency-basis for the same generation of memory). Combining a slower and a faster stick simply forces the faster stick to run at the speeds of the slower stick on a Mac, when the EFI reads these timing and frequency tables.
 

elf69

macrumors 68020
Jun 2, 2016
2,333
489
Cornwall UK
as max said I did this in a 2010 MacBook. one 1066 and one 1600 and it works fine at 1066 speeds.

no boot if two 1600 though.
 
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