RAM»DDR

DDR


184 Pins DDR Memory

DDR SDRAM (double data rate synchronous dynamic random access memory) also called DDR RAM is a memory integrated circuit which transfers double the data than its previous counterpart SDRAM (synchronous dynamic random access memory).

The continous quest for improved performance resulted in faster SDRAM's which could transfer data at double the speeds, this new breed of Memory circuits were called DDR RAM's. One important feature which was innovative in DDR RAM was its ability to transfer data during both the edges. It could transfer data in the rising edge as well as in the falling edge whereas SDRAM's were only able to transfer data during rising edge. So double the data could be transferred in a single clock cycle. The Architecture of SD RAM and DDR RAM remained same. DDR RAM was a perfect replacement for SDRAM's because the speed of the data transfer increased with less power utilized. DDR RAM is most efficiently used in applications where block transfers are necessary where data is transferred from memory to processor cache and vice-versa.

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Number of Pins


168 Pins SDRAM has two notch

The Number of pins in DDR RAM vary from Desktop Computers to Laptops. Desktop Computers DIMM's have 184 pins and Laptop computer DIMM have 200 pins. The operating voltage of DDR RAM is close to 2.5 V which is much lesser than 3.3 V consumed by SDRAM's. So with the use of DDR RAM, less power is consumed even though rate of data transfer is doubled.

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Speed

DDR SDRAM (DDR1) SDRAM DIMMs - DIMMs based on Double Data Rate (DDR) DRAM have data but not the strobe at double the rate of the clock. This is achieved by clocking on both the rising and falling edge of the data strobes.

  • DDR200 (PC1600) 100 Mhz Clock
  • DDR266 (PC2100) 133 Mhz Clock
  • DDR333 (PC2700) 166 Mhz Clock
  • DDR400 (PC3200) 200 Mhz Clock
  • DDR433/434 (PC3500) 216 Mhz Clock
  • DDR466 (PC3700) 233 Mhz Clock
  • DDR500 (PC4000) 250 Mhz Clock
  • DDR533 (PC4200) 266 Mhz Clock
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Compatibility

DDR RAM is generally made for processors 1GHz and faster. Designations like PC1600 DDR SDRAM and PC2100 DDR SDRAM coincide with particular FSB and CPU speeds. AMD and Intel use different schemes to designate processor speed, and the various technicalities in RAM designations and standards can be confusing. Check your motherboard manual to see what RAM type is compatible with your system before purchasing memory.

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Available Memory Sizes

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Installation