Question 1

Needing to find out when adding RAM on a MSI FM2-A85XA-G65 MOTHERBOARD if the RAM can be mismatched. 
I have= G.SKILL 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10666) and would like to add to the open slots 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10666); giving a total of 12GB of RAM. Can this be done on this Motherboard or not?
If not then what are my options, please

Accepted Answer

Most motherboards should be fine if you have 4GB in the first set of slots and 8GB in the second set of slots. Some motherboards may behave peculiar if you have high memory first and low memory second. Check your motherboard guide if a certain order is required.

Set up your memory and run MemTest 86 (or another memory testing program) for 24 hours. If you have problems, switch the memory modules around and re-test. If everything tests fine, boot up the operating system.

Question 2

grabbed a pair of these back late 2010 for a fresh build.
seemed to be the best choice for me on the QVL for my sabertooth p55.
I later grabbed another pair to bring me up to 8GB.
Currently got these OC'd to 1600mhz, at 9-9-9-24-2t, 1.5v, wanna try em at tighter timings!
  
Times are changing though and I am interested in going up to 16GB. I have had 0 issues with this RAM, was initially using them in XMP mode.

Gonna have to check the QVL, but could you suggest a 16GB kit? 
Id like to stay at 1600mhz, does that mean I should get a 1333 kit and OC, or just get a 1600 kit and have it already be at 1600mhz?

Accepted Answer

Depends on what you want to do with your current configuration. You could get two more of those exact sticks and over clock them to the same settings you used (if your motherboard supports that config) or replace those two sticks you currently  have and buy a 2X8gb 1600mhz kit.  If you want to overclock and push limits past your current 8gb config, I'd get the kit I mentioned since they will be more stable since they start out as 1600mhz stock speeds. So either get 2 more 4gb sticks and overclock or replace with the 16gb kit. It all depends on how much you want to spend.

Question 3

I bought 8GB of this memory in 2010, I would like to increase my memory to 16GB.

Do you sell memory that I can use in my motherboard: GIGABYTE GA-790FXTA-UD5 AM3 AMD 790FX SATA 6Gb/s USB 3.0 ATX AMD?

Accepted Answer

I could not speculate on your board, but know that for my board the RAM did not function and the modules has different version numbers 1.1 vs. 1.3 IIRC. My Intel DP-45G MB would not even boot the modules I received ... by themselves, so I sent mine back and am still stuck with 4GB RAM.

Brand	G.SKILL
Model	F3-10666CL8D-4GBHK

Capacity	4GB (2 x 2GB)
Speed	DDR3 1333 (PC3 10666)
CAS Latency	CL8
Timing	8-8-8-21
Voltage	1.50V
ECC	No
Buffered/Registered	Unbuffered
Multi-channel Kit	Dual Channel Kit
Heat Spreader	Yes
Features	Compatible with Dual Channel Intel Core i5 CPU for P55 chipset motherboard, Dual Channel Core i7 CPU for P55 chipset motherboard, and AMD AM3 Platform.
Recommend Use	High Performance or Gaming Memory

G.SKILL 4GB (2 x 2GB) DDR3 1333 (PC3 10666) Dual Channel Kit Desktop Memory Model F3-10666CL8D-4GBHK

Learn more about the G.SKILL F3-10666CL8D-4GBHK

Customer Reviews of the G.SKILL F3-10666CL8D-4GBHK

Warranty & Returns

Warranty, Returns, And Additional Information

Warranty

Return Policies

Manufacturer Contact Info

Item#: N82E16820231189