I currently have 8gb ddr3 ram and was thinking about adding another 8gb ddr3 ram stick but the same exact one i have right now is out of stock so if i get a different brand/model's 8gb ddr3 1600mhz stick, is there anything i should look for in terms of compatibility. I cant upgrade to ddr4 since my cpu/motherboard doesnt support, so will probably make a new pc after I graduate.