Yeah, 128GB DDR4 RAM in one stick, sounds impossible but it already exists. Big companies including Samsung, Crucial and Hynix started manufacturing modules at large scale a while ago now. It totally looks like standard RAM, but It has the largest capacity and the highest energy efficiency of DRAM module available today.
Your home pc probably won’t support 128GB of RAM and 32GB is still enough for gaming, the fact that 128GB DDR4 exists, is quite awesome. Even though, you are lucky to have motherboard that can handle 128GB of ram, there is something else you need to know about new modules…. So far, they are only produced for enterprise computer servers and YES, can’t get them cheap too. Prices vary, start from £1300 and go up to £5000.