[SOLVED] Mix Ram help

[Jakuu]

I'm trying to upgrade my ram and I was wondering if I am able to mix it. I currently have 2x Gskill RipjawsX F3-14900CL9D-8GBXL (link). I was wondering if I can put on a F3-14900CL10D-16GBXL (link) with my current ram.

I know that the voltage and Mhz has to match but what got me confused is do I look at the SPD speed or tested speed.

My CPU: Intel(R) Core(TM) i5-4670 CPU @ 3.40GHz, 3400 Mhz, 4 Core(s), 4 Logical Processor(s)
MOBO: MSI Z87-G43 (MS-7816)

 

[Phaaze88]

No one can give you a concrete answer on this. Modules with similar specs only increase your odds of it working; there are no guarantees that combination will work without issue.
It's one big lottery.

 

[Calvin7]

SPD speed or tested speed are for the memory in the form sold. The combination you are considering has no guarantee to be compatible together. There also are no guarantees as to how it would work if the system boots up.