memoria DIMM DDR diferencias

[Mithrandir]

Aqui esta el "tumbaburros" que he leído para salir de confusiones. Explica lo que comenta Santiago

Double data rate (DDR) SDRAM

Double data rate (DDR) SDRAM is a later development of SDRAM, used in PC memory from 2000 onwards. All types of SDRAM use a clock signal that is a square wave. This means that the clock alternates regularly between one voltage (low) and another (high), usually millions of times per second. Plain SDRAM, like most synchronous logic circuits, acts on the low-to-high transition of the clock and ignores the opposite transition. DDR SDRAM acts on both transitions, thereby halving the required clock rate for a given data transfer rate.

The DDR SDRAM standard is evolving, from DDR to DDR2 to DDR-3. At the time of writing (December 2004), DDR is still the main memory standard, but DDR2 is now supported by some chipsets and is beginning initial adoption. DDR2 is expected to become the major standard in 2005, while DDR-3 is under development and standardization within JEDEC has started. The difference between DDR, DDR2, DDR-3 is mostly in differing supply voltages, different speed classes, as well as some changes in the exact specification of the interface.

* DDR: supply voltage VDD = 2.5 V
* DDR2: supply voltage VDD = 1.8 V
* DDR-3: supply voltage VDD not yet standardized (draft specifications call for 1.2 to 1.6 V)

Y del cual del "DDR2 is expected to become the major standard in 2005" para disgusto de Intel no ha sido del todo cierto al dia de hoy