The system will take up to 2X16 = 32G RAM.  You're better off either upgrading the 8 to 16 with a matching soDIMM, or upgrading to 2X16 = 32.  While 8+16 likely will work, it result in only partial dual-channel operation -- the upper 8G will be in half-bandwidth mode.  
Hello, Dell community I am planning to upgrade my 24 GB RAM because I have 8 GB in my Laptop and I want to buy 16 GB RAM (8+16=24GB as total), is this possible because I did not find in the Dell 5570 specification 24 GB mentioned as a total memory. And is it true that I cannot put 32 GB RAM in a single memory slot [IMAGE]  
Dell Inspiron 15 5570 RAM Upgrade