Mine was 8 onboard and 8 on a sodimm. FX516PM-211.TF15.11 is my exact model name. I replaced the 8gb sodimm with something larger. I went with 32GB even though not officially supported, as I had one laying around from prior laptop, and it worked. so I have a weird sized 40GB of ram available. I haven't verified , this might be making the ram run in single channel mode, with a possible small performance hit for doing so (for not having same size ram for onboard + Sodimm). If someone who reads this can confirm, or showing a way to verify, would ge great.