Resolved RAM from 2011 mini incompatible with 2010 mini?

[indg]

i took the 2x2GB ram modules from the 2011 mini server and installed them into the 2010 mac mini (2.4ghz C2D) and the latter did not like it (just beeps upon bootup). i thought the 1333 mhz ram would just clock down to 1066mhz, but apparently something is goofy. has anyone else tried this and was successful?

 

[saulinpa]

Check to see if you seated the modules fully. I just moved the 2x2GB dims that came with my 2.5 i5 mini to my 2.66 C2D and it seems OK. I will let it run and see if there are any issues.

I assume the memory in the 2.5 is the same as in the server? Specs on Apple site show both as 4GB of 1333MHz DDR3 memory.

 

[Mak47]

My understanding is that it does not clock down. It won't work, at least from what I've been told.

Supposedly the other way around will, but that doesn't make much sense to do.

 

[saulinpa]

This morning I found my 2010 mini frozen. Time to put back the slower memory.

 

[indg]

i tried again today and the 2010 mini still would not accept the ram from the 2011 mini. even tried putting only one of the 2gb modules in the lower bank and turning it on and it wouldn't accept either module. put the 2x1gb modules back in and it fires right up.

@Mak47,
putting in pc3-8500 ram into the 2011 mini definitely shouldn't work as it requires pc3-10666 or higher. however it's supposed to work the other way around, but apparently not for me. weird.

 

[japtor]

I'm not sure about the mini, but I've heard about MacBooks that can take one module of higher speed RAM, but fail with two. Like 1066+1333 worked for them, but not 1333+1333 for whatever reason.

 

[tdfreeman]

After getting my heat issue ironed out, I did a little testing. I had 8GB 1066 sticks in my MBP 13 (2009). I took them out and swapped the memory in the new 2011 Mini. It's been a few days with both on constantly with no issues. If you look at the MBP, the memory actually says 4GB at 1333. The bus is only 1066 though. With the mini, memory shows 1066. I don't see the bus speed in the system info.

 

[saulinpa]

When I put the 2011 memory in my 2010 it did say 1333. Maybe it is really running at that speed but can't do it reliably?

 

[indg]

I'm not sure about the mini, but I've heard about MacBooks that can take one module of higher speed RAM, but fail with two. Like 1066+1333 worked for them, but not 1333+1333 for whatever reason.

you were right. this appears to be a common problem with the 2010 macbook pros with c2d and nvidia 320m.

so i put the 1066mhz module in bank0 (lower) and 1333mhz in bank1 (upper) and it worked. system profiler reports both speeds to be 1067mhz. so as long as one of them is 1066, it will clock down the 1333. i can live with that. 50% more ram is better than zero.