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DDR2
High-Performance Memory |
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DDR2 is an evolutionary enhancement over DDR. This technology is currently
the largest selling technology today and offers the best cost per bit. Most
new system designs today would likely choose to use DDR2.
It takes advantage of the DDR improvements to transfer data on both edges
of the clock. In addition, it further improves the speeds to provide standard
transfer rates of PC2-3200 (5.0 ns clock), PC2-4200 (3.75 ns clock), PC2-5300
(3.0 ns clock), and PC2-6400 (2.5 ns clock). DDR2 chips save further power
over the previous technologies because these chips use a standard voltage
of 1.8 volts.
- Low Power Consumption & System Cost
- Operating Voltage Only of 1.8 for DDR2 Compared to 2.5 in DDR
- Speeds for DDR2 can reach speeds as high as DDR2-800
- 40% Lower Power Consumption Than DDR-400
- Lower Heat Generation Allows Systems To Run Cooler
- Higher Density : Up to 8GB Modules (Using 2Gb Chips)
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Four standard operating frequencies for the DDR2 SDRAM Memory Module specification
were developed to provide the use with the most suitable option: PC2-3200,
PC2-4200, PC2-5300,
and PC2-6400.
PC2-3200 memory module configurations utilize DDR2-400 components to achieve
the highest performance, with a peak bandwidth of 3.2GB/s when used in systems
operating on 200MHz memory clock frequency.
PC2-4200 memory module configurations utilize DDR2-533 components to achieve
the highest performance, with a peak bandwidth of 4.2GB/s when used in systems
operating on 266MHz memory clock frequency.
PC2-5300 memory module configurations utilize DDR2-667 components to achieve
the highest performance, with a peak bandwidth of 5.3GB/s when used in systems
operating on 333MHz memory clock frequency.
PC2-6400 memory module configurations utilize DDR2-800 components to achieve
the highest performance, with a peak bandwidth of 6.4GB/s when used in systems
operating on 400MHz memory clock frequency.
DDR2 doubles the bandwidth available to your system and runs twice as fast as
regular DDR. DDR2 works very similar to DDR except that double the data bits
are fetched internally to enable transferring the sequential data at twice the
speed. Like DDR, the data is transferred on both the rising and falling edge
of the clock cycle enabling DDR2 to literally double the data transfer rate
of the original bus clock. For example; with DDR2 SDRAM, a memory running with
a clock of 333 or 400MHz will yield an effective data rate of 667 or 800 mega-transfers
per second (MTS), doubling the data rate.
| WILL DDR2 WORK ON MY SYSTEM? |
DDR2 is a technology supported by a newer generation of DRAM controllers
with DDR2 enabled logic. DDR2 DIMM modules are available in a variety
of form factors including 240 pin full-sized DIMM, 200 pin So-DIMM, 240
pin Very Low Profile (VLP) DIMM, 244 pin Mini-DIMMs, and 240 pin FB-DIMMs.
These form factors are not interchangeable with the preceding DDR or
succeeding DDR3 technology form factors.
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