PC Watch has published a set of documents linked to DDR4 that were published on the occasion of MemCon10, a conference on memory that took place at the end of July. For the moment, the DDR4 standard hasn’t yet been finalised but should be during 2011, for introduction in 2012 and full roll out not planned before 2015! So we’ll have plenty of time to see it coming.
As with every new DDR generation, DDR4 should double available bandwidth for identical memory cell frequency. Internal organisation will therefore be modified so as to double bandwidth and attain DDR4-1600, DDR4-2133, DDR4-2666, DDR4-3200 and even DDR4-4266! In terms of voltages, while DDR3 runs at 1.5V, with low tension 1.35V versions also available, here we’re talking a default of 1.2V with the possibility of going down to 1.05V, which means we won’t see energy consumption shooting up too high in spite of the increased speeds.
Another important change is that the bus used should be a point to point type, so as to support the higher frequency of the external memory bus. It will therefore no longer be possible to use more than one memory bar on the same channel, unless you use additional chips to serve as switches and which would need to be integrated in the server platforms.
This will push memory manufacturers to come up with ever denser bars, which should be possible with the arrival of 4 Gb and 8 Gb memory dies expected in 2011/2012 and 2014/2015 and which should lead to roll out of 8 GB and 16 GB bars.