F3-12800CL9D-4GBRL + Extra 2x4GB

[Airclot]

Hello,

First things first,
Motherboard: ASUS P7P55D-e Pro
CPU: Intel Core i5-760 Lynnfield 2.8GHz LGA 1156 (BX80605I5760)

Back in 2010, I bought for my computer the F3-12800CL9D-4GBRL 2x2GB. Over the past few months, I've noticed that I've been maxing out my ram, and figured it was time to add more, so 3 days ago I ordered the F3-12800CL9D-8GBRL 2x4GB to install next to my already 4GB, for a total of 12GB. Now, after reading up a bit more online, it seems some people are saying I cannot get these to work together happily, even though they are the exact same model, and bought from the same place (Newegg), just different amount of memory. I also heard that I would have to do some tweaking in the BIOS to ever hope to get them to get along.

So my question is, can I install the new 2x4GB memory next to my already installed 2x2GB? The 2x2GB is in DIMM_A1 and DIMM_B1 for dual channel operation, and I was planning on putting the 2x4GB in DIMM_A2 and DIMM_B2. If I can install it, where should I put my 4 sticks? Ideally I would like dual channel, but if that is not possible, single channel would be acceptable.

Also, can anyone give me a bit of a tutorial on how to set the settings in the BIOS? While I did build my own computer, I have very limited experience with the BIOS.

Thanks, that is all!

[Tradesman]

First off, any time you mix sets it can be problematic, even if they are the same exact model - that's why DRAM is offered in all different amounts of DRAM from 1-64GB and different number of sticks to fit Single, dual, tri or even quad channel mobos. But...there's always a but, it doesn't hurt to try and sets can often be made to play nice with minor voltage and/or timings adjustments. Generally the higher the density and freq the harder it is. 1600 is sort of borderline. Also XMP won't work as it's programmed to the sticks by the set, so you'll need to set up manually. I'd put the new sticks in A1 and B1 start it up, enable XMP and then shut down, then add the older sticks into A2 and B2 and boot into the BIOS, ensure the timings are correct and then manually set them to the same as they are in, change from XMp to manual, raise the DRAM voltage to 1.55, and raise the MC (memory controller) voltage (believe VTT on your mobo) up 0.05 from it's present setting and give it a try.