What is DDR3 Memory?
Tuesday, September 26, 2006
Several major DRAM manufacturer have made announcement, they are
supplying the industry's first DDR3 devices and modules to leading
PC industry developers for evaluation by early 2007. Intelís
Bearlake chipset will be the first to support DDR3 and it is expected
to arrive in the third quarter of 2007 Key Features
Component densities: standardized from 512Mbit thru 8Gbit.
- The DDR3 components are twice as fast as today's highest speed
DDR2 memory products.
- The first computer systems equipped with the advanced DDR3 memory
technology are expected to arrive in 2007.
- The main advantages of DDR3 are the higher bandwidth and the
increase in performance at low power.
- The DDR3 SDRAM devices will offer data transfer rates up to
1600 Mbps (megabits per second).
- The supply voltage for the memory technology is being reduced
from 1.8 volts for DDR2 to just 1.5 volts for DDR3 targeting a
work day equivalent of battery time. The voltage reduction limits
the amount of power that is consumed and heat that is generated
in connection with the increase in bandwidths.
The most important densities will be 512Mbit and 1Gbit at the beginning,
later on a 2Gbit and eventually 4Gbit component to follow.
Module densities: from 256MByte up to 8GByte for standard
Higher module densities beyond 8Gbyte for special applications like
servers may be introduced later on.
DDR3 SDRAM Components:
- Introduction of asynchronous RESET pin
- Support of system level flight time compensation
- On-DIMM Mirror friendly DRAM ballout
- Introduction of CWL (CAS Write Latency) per speed bin
- On-die IO calibration engine
DDR3 Feature Comparison
||200 ~ 400 Mbps
||400 ~ 800 Mbps
||800 ~ 1600 Mbps**
||2.5v +/- 0.2V
||1.8v +/- 0.1V
||1.5v +/- 0.07V
|60 BGA FOR 4/x8
84BGA FOR x16
|78 BGA for x4/x8
96 BGA for x16
(Single ended Default)
||BL = 2,4,8
|BL = 4,8
|BL = 4,8
|# of bank
||512Mb : 4banks
1Gb : 8banks
|512Mb/1Gb : 8banks
2Gb/4Gb/8Gb : tbd
||Off-Chip Driver Calibration
||Self Calibration ZQ Pin
Features Have been fixed in JEDEC.
by DDR3 System Assumption is under discussion.
DDR3 supports 1600Mbps under 1slot/channel system.
And, the Possibility of DDR 2-slot/channel system being
discussed in JEDEC.
- Fly-by command/address/control bus with On-DIMM termination
- High precision calibration resistors
Elpida DDR3 DIMM module
Advantages compared to DDR2
- Higher bandwidth (up to 1600 Mbps)
- Performance increase at low power
- Longer battery life
- Enhanced low power features and thermal design
DDR3 SDRAM will be packaged in a DIMM modules form factor.
Memory market research company iSuppli expected DDR3 DRAM
products to replace their predecessor DDR2 as the main volume product
in 2008. iSuppli forecasts a DDR3 market share of 55% the same year.
IDC predicted that the first DDR3 memory will be commercially sold
in 2006, whereas in 2009 market share of DDR3 will be 65%.
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