Nope - not the CPU. As TG said above, as long as your motherboard can handle it, you should be good to go.
But I think you should start looking on your motherboard's website. Find your motherboard and there should be a "QVL" - qualified vendors list. This will be a list of RAM they have tested and verified is compatible with your board. You don't have to buy off that list, but it will show you the RAM specifications/characteristics of RAM that works.
I've always like Crucial and Corsair, but I've been buying a lot of Mushkin lately and have been very pleased. But in reality, almost all RAM has a lifetime warranty so it is hard to go wrong with any brand, as long it is compatible to begin with.
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