DRAM and It's types

As in the previous article I have explained about what actually the RAM is and the typesof RAMs with their internal working in detail. I request you to please go through the above articles.

DRAM stands for the the dynamic random access memory. DRAM is the RAM which need to be refreshed thousands of time in one clock cycle. The reason is due to the architecture of the DRAM.

The size and the speed of the DRAM is less than the SRAM. 

Now if we talk about the types of DRAM. There are mainly two types of DRAM.

1. Asynchronous DRAM

2. Synchronous DRAM (SDRAM)

In Asynchronous DRAM the clock is not given to each memory bit at the same time therefore it consumes more time to give the output (this condition is called as delay).

Whereas in synchronous DRAM the clock is given in common to all the memory bit cells. Due to which all the bit cells are operational at the same time and no delay occurs

Further the SDRAM is divided into two types.

1. Single data rate SDRAM

2. Double data rate SDRAM (DDR SDRAM)

Now in the the single data rate RAM the data is only transferred when the clock pulse shows 1. Whereas in the double data rate the data is transferred at the clock pulse zero as well as one. This concludes that the double the amount of data is send in every clock pulse by DDR SDRAM as compared to SDRAM. 

Now the SDRAM are not been used now, we are using the DDR SDRAMs as they are faster, cheaper and reliable.

Now the DDR SDRAMs are further classified according to their differing generation.

The different generation is

       1.     DDR1 SDRAM

         2.      DDR2 SDRAM

3    3.   DDR3 SDRAM

4    4.   DDR4 SDRAM

DDR SDRAM stands for Double Data Rate 1 Synchronous Dynamic Random Access Memory . This was the first RAM introduced in the category of the double data rate.

1. DDR1 SDRAM (Double Data Rate 1 Synchronous Dynamic Random Access Memory)

·       

•       Release date: 2000
• ·        Max clock Rate: 266 MHz(x2)
• ·        Bandwidth: 4.2 GBps
• ·        DIMMs Pins: 184 pins
• ·        Voltage Required: 2.4 volts (approx)

2. DDR2 SDRAM (Double Data Rate 2 Synchronous Dynamic Random Access Memory)

·       

•       Release date: 2003
• ·        Max clock Rate: 800 MHz(x2)
• ·        Bandwidth: 8.5 GBps
• ·        DIMMs Pins: 240 pins
• ·        Voltage Required: 1.8 volts (approx)

3. DDR3 SDRAM (Double Data Rate 3 Synchronous Dynamic Random Access Memory)

• ·        Release date: 2007
• ·        Max clock Rate: 1600 MHz(x2)
• ·        Bandwidth: 12.8 GBps
• ·        DIMMs Pins: 240 pins
• ·        Voltage Required: 1.5 volts (approx)

4. DDR4 SDRAM (Double Data Rate 4 Synchronous Dynamic Random Access Memory)

·        

•       Release date: 2014
• ·        Max clock Rate: 3200 MHz(x2)
• ·        Bandwidth: 25.6 GBps
• ·        DIMMs Pins: 288 pins
• ·        Voltage Required: 1.05 volts (approx)

There is also an important concept of the channels in the ram. For the information related to the channels in the ram do read my next blog on RAM.

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