Ram question

[philliplakis]

Hey
can i use my ram from my mini
Crucial 16GB (2x 8GB Kit) PC3L-12800 Unbuffered 204-pin SO-DIMM

in my Macbook Pro?
Crucial 16GB (2x 8GB Kit) PC3L-10600 Unbuffered 204-pin SO-DIMM

The only difference i see is the mhz speed
The mini is 1600
and mbp is 1333

Will it down clock like a tower would?

I know that in my tower i have 1333 running @ 1060

Just curious if the same will happen in a MBP?

 

[dusk007]

Sure you can. It will run it as slow as the memory controller supports. You can always use faster RAM, they usually have spd settings saved for each step 1066/1333/1600/++

 

[philliplakis]

Sure you can. It will run it as slow as the memory controller supports. You can always use faster RAM, they usually have spd settings saved for each step 1066/1333/1600/++

and it didn't work...

just incase anyone reads this as tries.

 

[simonsi]

Out of interest, did you get memory-test failure beeps on boot, or did it initialise the memory but crash in use?

 

[philliplakis]

Out of interest, did you get memory-test failure beeps on boot, or did it initialise the memory but crash in use?

Once i got the 3 beep and the other three times it booted and just after the apple sign i got a X in its place.

 

[maflynn]

Odd, I've seen faster ram work in computers that only accept slower ram

 

[philliplakis]

Odd, I've seen faster ram work in computers that only accept slower ram

Me too.

I had a Mac Pro running 1333mhz ram @ 1060mhz



Maybe its with laptop issue, cause in the desktop world it would work....

 

[drambuie]

DIMMs usually have tables showing the specified frequency vs latency combinations for the RAM. The 1600MHz DIMMs would probably show latency values for 833, 667, and possibly 533MHz, clock rates. DDR RAM runs at twice the clock rate.

It could be that the 1600MHz RAM shows a latency for 1333MHz that the MBP can't adjust to, or the MBP is trying to run the RAM at 1666MHz and failing. It could be a firmware limitation.

 

[204353]

From experience, I've seen quite a variety of results when attempting to use faster RAM in a Mac.

I think the main determinant is what the chipset/processor supports. For example, the Sandy Bridge chip in my MacBook Pro can support 1600MHz RAM (what I have fitted right now) and runs it at full speed, despite Apple's specs saying 1333MHz is what you need.