In computer memory have several types of RAM (Random Access Memory). But the most popular RAM are SDRAM (Synchronous Dynamic Random Access Memory) and DDR RAM (Double Data Rate Synchronous Dynamic Random Access Memory).
Both SDRAM and DDR RAM are used in computer memory, but the main deference is in their architecture, speed and some functionality. This article will explain the main deference between them, and it core features.
What is DDR(DDR RAM)?
DDR RAM, also called as Double Data Rate Synchronous Dynamic Random Access. It is a type of RAM in which that reads or writes two words of data per clock cycle by using the rising and falling edges of the clock signal. DDR RAM have a synchronous interface, which means that it waits for a clock signal before responding to regulate inputs and is thus synchronized with the computerâs system bus.
How DDR Works
DDR is faster than the SDRAM because it transfers the data in twice speed than the SDRAM. Also, DDR required less voltage to run.
What is SDRAM?
SDRAM typically refers to initial generation Synchronous DRAM, which is slower than resulting generations (DDR) as a result of only 1 word of knowledge is transmitted per clock cycle (single data rate).
The second generation of synchronous DRAM memory chips was DDR (sometimes known as DDR1). DDR stands for double rate, which suggests the chip reads or writes 2 words of knowledge per clock cycle. The DDR interface accomplishes this by reading and writing information on each the rising and falling edges of the clock signal.
Additionally, some minor changes to the SDR interface temporal arrangement were created in savvy, and therefore the offer voltage was reduced from three.3 to 2.5 V. As a result, DDR SDRAM isn't backward compatible with SDR SDRAM.
How DDR RAM Works
SDRAM typically refers to the initial generation of Synchronous DRAM, which is slower than subsequent generations (DDR) because only one word of data is transmitted per clock cycle (single data rate).
Difference between DDR and SDRAM
| SDRAM | DDR |
|---|---|
| It refers as synchronous dynamic random-access memory | It refers as Double data rate SDRAM |
| SDRAM has 168 pins and two notches at the connector | DDR has 184 pins and a single notch at the connector. |
| SDRAM was released in 1997 | DDR RAM was released in 2000 |
| SDRAM has less speed in comparison DDR | DDR can transfer data at roughly twice the speed of SDRAM. |
| it's working on 3.3 volts | it's working on 2.5 Volts (standard); 1.8 V (low voltage) |
| SDRAM speed is considered as 66 MHz, 100 MHz, 133 MHz | DDR working on speed as 200 MHz, 266 MHz, 333 MHz, 400 MHz |
| SDRAM's Internal rate range is (100 Mhz-166 MHz) | DDR's Internal rate range is (133 MHz - 200 MHz) |
| Data rate of SDRAM is (0.8-1.3) GB/s | Data rate of DDR is (2.1-3.2) |
| SDRAM prefetch timing is 1ns | DDR prefetch timing is 2ns |
| SDRAM is waiting wait for the completion of the previous command to be able to do another read/write operation. | DDR is not waiting wait for the completion of the previous command to be able to do another read/write operation. |
Conclusion
This article conclude that main deference of SDRAM and DDR RAM is in their functionality. By understanding this it will be easy to figure out the right type of RAM for your computer.
