Adding memory... able to mix?

[Celgadis]

Hi! I currently have this:

Asus P8P67 PRO Rev 3.1
i5-2500K @ 3.3Ghz
2x2Gb G.Skill Ripjaws DDR3-1600 PC3-12800 CL-9-9-9-24
Asus DirectCU II TOP R9 280 3Gb

I use my pc mainly for gaming so I need to upgrade ram to, at least, 8GB but I'm a little low on budget xD.

So my doubts are... should I buy another 2x2GB of the same memory I have and use the 4 slots (I think this is the cheapest way to achieve 8GB) or should I buy another single 4GB stick with the same brand and timings? Maybe I should replace it all with a new 2x4GB set?

My mains concerns are the budget and the compatibilitty.

Thanks a lot in advance!

 

[Spudmaster]

Buy two 2GB sticks of the EXACT SAME memory that you already have.

 

[Celgadis]

Thanks a lot.

I've been looking prices around and the 2x4GB are onlye 20€ more expensive than the 2x2GB so, is it worth it?

I mean, is dual channel better/faster then using the 4 slots? Also, if I use all slots now and need to add more ram in the future I will have to replace all slots, isn't it?

If I finally buy a new 2x4gb set, are the GSkill Ripjaw DDR3-1600 PC3-12800 CL-9-9-9-24 good or should I get something different in that price range?

Thanks a lot again!

 

[Tradesman1]

Get the 2x4GB that way you have 8GB and then if your old sticks will play with the new it's like a bonus as there are no guarantees when mixing sets that they will play together, it's a crapshoot

 

[Celgadis]

Thanks a lot! I will do so!

Just one thing... I still have to try but I have a big CPU fan and the Ripjaw may not fit well. If I get the Ares (for the low profile) with the same speed, CL and voltage, is it still possible to try to use them with my old Ripjaws? I know is a crapshoot, but, would it be possible?

Also, if I mix 2x2gb and 2x4gb and it works, will I get 12Gb working on dual channel?

Thanks a lot

Edited: I will not do any kind of overcloking... just plug the ram and leave it on its own