Posted on Thursday, September 13 2012 @ 16:26 CEST by Thomas De MaesschalckThe DDR4 memory standard is running late though, it was supposed to be finalized in 2011 but now finalization is planned for the end of this year and adoption isn't expected until 2014.
Samsung's roadmap reveals 2400MHz DDR4 samples should arrive next year, and by the time servers start adopting DDR4 it should have modules operating at 2666MHz, with a further bump to 3200MHz planned for after 2014. When DDR4 will arrive for desktops and laptops is still unknown.
A DDR4 voltage roadmap has been proposed that will facilitate customer migration by holding VDDQ constant at 1.2V and allowing for a future reduction in the VDD supply voltage. The per-pin data rates, over time, will be 1.6 giga transfers per second (GT/s) to an initial maximum objective of 3.2GT/s. Other performance features planned for inclusion in the standard are a pseudo open drain interface on the DQ bus, a geardown mode for 2667MHz data rates and beyond, bank group architecture, internally generated VrefDQ and improved training modes.
The new levels of performance will require a tradeoff. In DDR4 memory sub-systems every memory channel will only support one memory module. As a result, to enable highest-possible memory capacities, DRAM makers will make high-capacity DDR4 chips using through-silicon-via (TSV) technology that will allow to increase capacity of memory chips at a very fast rate. For servers, special switches will be introduced to avoid one module/one channel limitation. As a result, server platforms will be able to accommodate much higher memory capacities than they can do now thanks to new levels of module capacities.
Source: X-bit Labs
