Upgrading MacBook Pro mid-2009 RAM
I'm trying to upgrade my MacBook's RAM to 8GB (2x4 GB), but somehow when I install the new cards I got the 3 beeps + 5 seconds pause. The 4GB cards were already working in another early 2011 MacBook.
The point being that, if I install the memory in a mid-2009 in a 2GB+4GB configuration, the Mac runs well. I have tried to switch cards and slots and it works, too.
Does anyone know what's happening?
3 beeps + 5s pause means your memory failed training. There are a LOT of reasons this happens. Let’s consider the most common.
First, let’s make sure your system supports 8 GB. According to Apple, the mid-2009 MacBook Pro does support up to 8 GB:
4GB (two 2GB SO-DIMMs) of 1066MHz DDR3 memory; two SO-DIMM slots support up to 8GB
Now let’s consider a couple of possibilities:
- It may be that one of your 4 GB SO-DIMMs is of marginal quality and is failing during one of the training steps. Let’s rule that out. When you ran your experiment, did you try both of the DIMMs alongside the 2 GB DIMM? And then did you try each of those DIMMs in the other slot alongside the 2 GB? In other words, you should have performed this experiment with FOUR different memory configurations.
- Although I can’t think of a good reason why it would only happen for the 4+4 case, your firmware may not be recognizing a new DIMM has been installed and is trying to use a stale memory training table with the new card. You can force full memory retraining by resetting your PRAM (OptionCommandPR during boot).
My bad! It was a matter of the frequency.
The 4 gb cards are 1600 MHz and the max admitted by mid-2009 is 1066 MHz.
When installing 2 gb (1066 MHz) + 4 gb (1600 MHz), the macbook automatically slows down the speed of the highest to the lowest one. But if both 4 gb are installed, the Macbook gives the error. That's it.
Thank you for the advises.
I am not the world's leading RAM expert, but Crucial are not bad at this ;)
Checking their RAM recommendations for the 2009 Macbook Pro vs the 2011 gives this…
2009
2011
I would guess that they are sufficiently different spec as to not be cross-compatible.
My only guess for why one old/one new works is that the new is ignored & the old is sufficient to boot from.
If you check About this Mac from the menu & click the Memory tab, you should be able to see some variation of this, which will tell you which modules are recognised (this pic from a vastly different Mac, of course, I don't have a Macbook to grab a screenshot from). Empty slots show as empty, bad RAM shows with an error symbol.
Here are the pages I got that info from…
https://uk.crucial.com/compatible-upgrade-for/apple/macbook-pro-(13-inch--mid-2009)
https://uk.crucial.com/compatible-upgrade-for/apple/macbook-pro-(13-inch--early-2011)