RAM speed dependent on CPU model?

[Doc69]

I have a 2010 2.8GHz Quad Mac Pro. I understand that it can use both 1067MHz and 1333MHz RAM sticks, but that it will only run at 1067MHz regardless.

However, I think I read somewhere that if I upgrade the CPU to a 6-core 3.33 W3680, then the computer will be able to run the RAM at 1333MHz. Is this correct? If so, then I should probably order 1333MHz ram instead of 1067MHz in order to be ready if I decide to upgrade the CPU in the future.

 

[Umbongo]

Correct. Only buy 1333MHz DIMMs.

 

[deconstruct60]

I have a 2010 2.8GHz Quad Mac Pro.
.....
if I upgrade the CPU to a 6-core 3.33 W3680, then the computer will be able to run the RAM at 1333MHz. Is this correct? If so, then I should probably order 1333MHz ram instead of 1067MHz in order to be ready if I decide to upgrade the CPU in the future.

In part the Quad part is a 3500 series and the hex part is a 3600 series. The memory speed is being partially driven by different the generations. If you were planning to bail for an Xeon E5 later , its memory speed might be a consideration too if in next year or two.

 

[Doc69]

If you were planning to bail for an Xeon E5 later, its memory speed might be a consideration too if in next year or two.

Unfortunately I don't understand what you mean?

Are you saying that the Xeon E5 CPU (I assume Sandy Bridge?) will fit in the 2010 Mac Pro, or are you asking if I will take my current RAM over to the next Mac pro model (which I assume is DDR3 1600MHz)?

Correct. Only buy 1333MHz DIMMs.

Thanks!

 

[deconstruct60]

Are you saying that the Xeon E5 CPU (I assume Sandy Bridge?) will fit in the 2010 Mac Pro, or are you asking if I will take my current RAM over to the next Mac pro model (which I assume is DDR3 1600MHz)?

It is not about the CPUs.

The E5 systems take RAM DIMMs just like the current ones do. If a reasonable chance going to move DIMMs from one Mac Pro to the next then you can buy the next's faster DIMMs and won't have to rebuy later.

However, memory gets cheaper if you wait longer. Faster memory is typically more expensive now than it is later. If it is going to be 2 (or more) years when make the move then it is often better to buy the memory then. Likewise, it doesn't matter if not going to move memory between units (e.g., assign old Mac Pro to another task with its DIMMs and get another newer one. )


Similarly, if buying memory for an very old machine the memory prices are also higher.