no you can't your mobo supports DDR3 RAM but if you want 16 GB (which is MOBOs maximum) you have to use 2 x 8GB DDR3 or DDR3L RAM, you have only 2 dimm slots. So it's 2x 4GB as you have already or try switching them with 2x 8GB RAMs. Trying second solution, I would recommend you look for paired dual kit RAMs to lose any problems, your mobo could have problem reading 2 of them if they ain't same brand, model, bus speed, timings, etc.. So I would recommend using 2 confirmed dual kit RAMs