|
|
Generally our computers support any one of these SDRAM, DDR1, DDR2 or DDR3 RAM types, as each one has different electrical and physical characteristics.
SDRAM
Synchronous Dynamic RAM: This is earliest and slowest among all the above ones and data is fetched on a single edge of the clock cycle. This is synchronous with the clock of the system.
DDR
Double Data Rate: This is almost twice as fast as SDRAM because the data here is fetched on both edges of the clock cycle. It also uses low power so great to use in laptops.
|
This is also called as DDR SDRAM because this is also synchronous with system clock. The three generations of DDR memory are DDR1, DDR2 and DDR3.
|
|
Speed>
|
Explanation
|
Example
|
|
DDR1
|
400MHz and a 64-bit data bus
|
Now-a-days it is becoming outdated
|
SAMSUNG 1GB PC3200 400MHZ CL2.5 DDR
SDRAM - $70
|
|
DDR2
|
staring speed of 400 MHz and provides
up to 800MHz and a data bus of 64 bits
|
Physically incompatible with DDR.
|
SAMSUNG 1GB DDR2 667MHZ PC2-5300 CL3
NON-ECC 240 PIN DIMM- $37
|
|
DDR3
|
Starting speed of 800MHz and can provide
up to 1.6Gbps but consumes low power than DDR2
|
1. Has interrupt reset for system
flexibility
2. Able to control the voltage fluctuations
3. Provides robust and high performance
operations.
|
Aeneon 1GB DDR3 PC3-10600 1333MHz
240-Pin SDRAM DIMM- $60
|
|
Still many computers are using DDR2 today. It is better to first find out the RAM specifications provided by the CPU manufacturer of our computer. And then choose the RAM according to the specifications because it has to be compatible with our computer.
Whenever we buy two memory modules with different speeds like one with 256 MB and another with 512 MB then the memory runs at the speed of the lower one which is 256 MB.
And there is no rule that we should buy all of the memory modules from the same manufacturer. We can add each one from different manufacturer. Some of the companies manufacturing RAM are Micron, Dell, Samsung, OCZ Technology, Kingston Memory Products, Corsair, etc.
|
