contains interesting data about both of them. the full story is available here: http://www.lostcircuits.com/memory/ddr3/
| QUOTE |
| The second generation of double data rate memory, that is DDR-II, has finally made its first, sparse appearance in the retail channel. Originally, DDR-II was shown on the different roadmaps scheduled for the third quarter of 2002 to enable 400 MHz data rate DRAM. Indeed, looking back, the highest speedgrade officially available in Q4 2001 and Q1 2002 was PC2100 or DDR266. Suffice it to remind our readers that at this point the official standpoint in the DRAM industry was still that there was no ramping of the operating frequency possible unless the form factor was going to be changed from a thin small outline package (TSOP) to a ball grid array (BGA). Arguments in favor of the BGA form factor centered on the lower impedance and shorter trace length of a solder ball compared to a standard “leg” of the TSOP design. |
| QUOTE |
| DDR (I) is approaching the end of its dominating role in the desktop space to be replaced by the second generation of double data rate memory starting at 400 MHz and using a conventional 64/72 bit parallel bus interface. Lower operating voltage, new features like on-die termination, off-chip driver calibration, Posted CAS and variable write latency sound intriguing but what is really lurking behind the new standard. We have seen claims of up to 72% power savings over DDR I and other miracle cures for any bandwidth issues faced by the PC industry. We have done the math ourselves found a few convenient errors in some of the manufacturer's descriptions of DDR II. Otherwise, DDR II looks very promising but who will benefit in the end? |