They do not necessarily need to be the same.
As long as the ram is the same speed, and same voltage the manufacturer has not a lot to do with it.
Apart from quality
Even if it is a slightly slower speed the BIOS should automatically detect this and throttle back the higher speed stick to the lower speed. If it jams the BIOS then the BIOS needs to be flashed to upgrade.
On my DAW PC for example, I have 8gig of ram. 2 sticks from Kinsgton and two "generic" brand sticks.
They are the same speed, voltage and capacity, but different manufacturer. No problems at all. And I have run tests (believe me
) that show all four sticks are running at full capacity.
And I can also confirm the Zalman CNPS7000C-AlCu CPU coolers also fit very nicely.
I can also confirm that if run a quad core inside the MS series, be prepared for either a very noisy fan, or a CPU running at nearly max heat levels most of the time. As the interior of the MS has very restricted airflow, being so small.
And because the MAX size of a system fan (the one near the power supply) is an 80mm one, you are limited in how much air you can pull from the inside without a cacophany of fan noise.
I have also made a hardware mod to fix this also. Previous mainboard temp 58 degrees, now it runs pretty constant at 39 degrees.
Now I know there are some that say a CPU can run "safely" at high temps, as long as it is within the spec, but personally I think having a safety margin of the CPU running at a constant temp of within 35% of the max, gives a better performance and longer life.
I am NOT disputing Domenico at all, just giving you my experience with it.