1333MHz SODIMM in late 2009 iMac

Question

NMO472 Author

Level 1

8 points

1333MHz SODIMM in late 2009 iMac

I have a late 2009 iMac 21.5". It has 2x2GB RAM pieces and two empty slots.

I have two old 2GB SODIMM 1333MHz RAM pieces from my old 2011 MacBook Pro (I put 2x8GB pieces in it).

Can I put the old 1333MHz 2GB pieces into the two empty slots in the late 2009 iMac 21.5" which runs 1066MHz?

Apple just says they are different memory, you can't use them.

Other people on this forum say that if it's Apple compatible memory the 1333MHz RAM will just clock down and work fine in the iMac, despite the different nominal speeds.

Anyone with any views?

Many thanks !!

iMac, iOS 10.3.3, Late 2009 21.5"

Posted on Sep 14, 2018 9:44 AM

Reply

Answer 1

NMO472 Author

Level 1

8 points

Sep 16, 2018 5:12 AM in response to dialabrain

Many thanks!!

I put the two 1333MHz pieces in, and turned it on and it appears to be working fine!

I didn't do any timing of any processes before I added the RAM, so I don't have an objective assessment of whether or not it's faster now. Subjectively, I think it is running faster (but that's me, and I know I've put the extra RAM in, so I guess I'm expecting to see it running faster).

Any suggestions about any standard processes that I could time, with and without the additional RAM, to see if I could get an objective measurement of whether it's running faster?

Many thanks !!

Reply

Answer 2

dialabrain

Level 10

136,127 points

Sep 16, 2018 5:05 AM in response to NMO472

Well at this point, since your iMac is considered by Apple to be vintage and they or an AASP will no longer work on it, I guess it can't hurt to try it and see. It won't blow up in any case.

Reply

Answer 3

NMO472 Author

Level 1

8 points

Sep 16, 2018 1:43 PM in response to dialabrain

Yes, you're right.

Happy is enough

Reply

Answer 4

NMO472 Author

Level 1

8 points

Sep 16, 2018 5:08 AM in response to rkaufmann87

Thanks !!

There were two pieces of 1066MHz RAM in left and right top slots, so I put the two 1333MHz pieces into the left and right bottom slots.

Does that match what you describe as using matched pairs of RAM?

Any suggestions about standard processes that I could use to test objectively whether the additional RAM has made the machine faster?

Many thanks !!

Reply

Answer 5

dialabrain

Level 10

136,127 points

Sep 16, 2018 5:42 AM in response to NMO472

You're welcome. I would say, if it seems faster, you don't really need to measure it.

Reply

Answer 6

rkaufmann87

Level 10

148,494 points

Sep 16, 2018 5:06 AM in response to NMO472

We always recommend that you use matched pairs of RAM, however as dialabrain said, it can't hurt to try. Worst case is it will not fit or work at all. If that is the case, simple remove the RAM.

Reply

1333MHz SODIMM in late 2009 iMac

Similar questions