While AMD’s Ryzen is sill a few months away, the JEDEC is now close to finishing the DDR5 standard which is expected to be done by year’s end.
DDR5 will increase the maximum capacity. At present consumer DDR4 is being mass produced at 4GB and 8GB capacities with 16GB at the high end. DDR5 will bump this up to at least 64GB maximum.
The JEDEC will have to add more wait-states to keep up with CPU speeds. Still the eventual bandwidth should reach 64 GB/s or more,.
Intel’s Optane is just now starting to enter the market and it may put some pressure on the need for more memory. With speeds faster than SSD products the phase change Optane may push DDR5 requirements back for consumers by 12-18 months.
With the adoption of M.2 the SSD has now been provisioned with more bandwidth that again pressures the need for consumers to install vast amounts of memory.
Facebook and a few others may need more RAM but they are in the minority. Some supercomputer systems may also need more memory. Hyper-V servers need lots of memory to be able to run more guest instances.
Consumer machines with DDR5 slots may be available in 2022,