Crucial has said on its promo page that DDR4 memory will be available to buy before the end of the year. Meaning this super RAM could be in your PC before Christmas.
You’ll need a new motherboard to run DDR4, but it sounds like it will be worth it. The new memory will manage to run at 2133MHz, double the speed of DDR3’s 1000MHz, but while using 20 per cent less power at just 1.2 volts. It should also manage to pack in 300 per cent more density, meaning the smallest size will start at 4GB.
Why is density important? This is the number of gigabits that can fit on a single memory module. So where 4GB previously would fit there can now be 8GB taking up the same amount of physical space. So much can DDR4 handle that a single unit will go up to 16GB. Most computers come with two RAM slots so that's 32GB you can run - paving the way for super speed computers.
So while laptops will have longer battery lives and run even faster we probably won’t see motherboards that support the memory at a reasonable price for a while. Nor will DDR4 be cheap. Expect to see DDR4 replace DDR3 in new computers off the shelves by late 2014 to early 2015.