[Rev2Liv]

I'm running a unibody Mid 2010 Mac Mini Server w/10.6.8. I recently upgraded the RAM to full 8GB. I used Crucial DDR3 1333mhz SO-DIMM modules.

The specs for this machine say that it has an FSB of 1066mhz. However, when I hit the 'About this Mac' button, for Memory, it reads, '8GB 1333 MHz DDR3'

I'm confused. Is it just recognizing the SPD info off the RAM modules? Is it running at 1066 of 1333? How do I find out?

Mac mini Server (Mid 2010) - Technical Specifications

[P]

The 2010 Mac mini uses a Core 2 Duo with Intel's old system design. This design means that the CPU does not have direct communication with RAM - it goes by way of a chip called the Northbridge or MCH. In this case, that chip is the nVidia 320M, which also integrates graphics and many other things that used to be in another chip on the motherboard.

The FSB (front side bus) is the bus between the CPU and the Northbridge. That bus runs at 1066 MHz. There is also the memory bus, which runs between the Northbridge and the RAM. That bus runs at 1333 MHz. This means that you have more bandwidth between RAM and Northbridge than you have between CPU and Northbridge - in fact, you have a lot more bandwidth there, because that communication is 128 bits wide each clockcycle, and the FSB is only 64 bits. The reason for this is that there are other things in the system that need to communicate with RAM - most importantly in your case, the integrated graphics - so the required bandwidth at that stage is greater.

Upgrading your computer with faster RAM will not generally help the CPU, but it will help graphics performance in some cases.

[Waragainstsleep]

My Late 2008 MBP also recognised 1333MHz RAM when I installed it, even though it only runs the RAM at 1066MHz. It really didn't like the 1333 and was flaky as hell, but it did know what speed it was somehow.

[Rev2Liv]

Originally Posted by P 

The FSB (front side bus) is the bus between the CPU and the Northbridge. That bus runs at 1066 MHz. There is also the memory bus, which runs between the Northbridge and the RAM. That bus runs at 1333 MHz.

Upgrading your computer with faster RAM will not generally help the CPU, but it will help graphics performance in some cases.

Does this mean that i'll see zero benefit to running 1333MHz RAM since 1066MHz is the limiting factor? I wish barefeats would do a speed comparison.

[P]

Originally Posted by Rev2Liv 

Does this mean that i'll see zero benefit to running 1333MHz RAM since 1066MHz is the limiting factor? I wish barefeats would do a speed comparison.

They have, several times, if you look far enough back. The end result is like I said: It helps graphics scores a bit, but nothing else. OTOH, it doesn't hurt either.