What ram can I mix with 2 4gb gskills?

[d0ra]

I have this memory: http://www.gskill.com/en/product/f3-2133c9d-8gab
G.SKILL Ares Series 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 2133 (PC3 17000) Desktop Memory Model F3-2133C9D-8GAB

I have this mobo: http://us.msi.com/product/mb/Z77AG43.html#hero-overview
MSI Z77A-G43

Question:
Can I put 2 8gb sticks in with my current 2 4gb sticks?

 

[Emerald]

Most likely not

the memory would have to have the same timing and latency values than your current one, 9-11-10-28-2N.

Add another pair like the one you have now. 16GB is usually more then enough memory.