RAM question.

My motherboard has 6 slots for RAM and this is what I have at the moment:

http://www.newegg.com/Product/Product.aspx?Item=N82E16820231304

It's 3 2GB sticks, so 6GB in total. I was going to buy the same thing again so I would have 12GB in total. However here's the thing, I have like 35$ in Best Buy's reward zone certificate which I thought I'd use that and save myself some money. Now when I check their site obviously Best Buy doesn't have shit when it comes to upgrading your PC. They don't have the same RAM that I have in my computer right now. I know having the same brand of RAM in your computer is recommended, but how much of a difference does it really make? Is it a very minor difference? Is it something noticable when doing 3D modeling and rendering? If so which brand should I get from best buy's site (something around 60$ before I use my certificate), or should I just stick with buying the same brand and spec that I have right now? I mean I could get the Nvidia GTX 680 and use the certificates towards that but they're out of stock on that and till I get my other 80$ or so in reward zone certificates it might be another 2 months. I mean either way it's not a huge big deal to me in trying to save 35$ but if the RAM difference is not really a big deal then I rather save something now.

 

now a days the brand of your RAM is pretty much irrelevant. As long as it is the same spec that is the key. Check the speed and CAS and as long as they match you will be fine I have a mix of Crucial and Kingston in my rig and it is fine.

 

And check that the voltage matches also

 

Thanks for the responses everyone, I believe I'm going to get a couple of 1G sticks and see what that does for me. I wish my old computer had more slots so I wouldn't have to waste the two 512's I have in there.