What is the difference between SDRAM and DDR RAM?  

yaar jatin bhai dekh, ddr ram bole to doubl cut ram on the basis of your hardware, and sdram contains single cut, ddr is the updated ram and can transfer the data fast as compared to sd ram of same unit....

Answered by Karan , an ibibo Citizen, at 9:34 PM on October 24, 2008

DDR standards for "Double Data Rate". DDR can transfer data on both the rising and falling edge of the clock signal, whereas standard SD ram can onle transfer data on one or the other. This means data throughput on DDR memory is twice as fast, hence the name "Double Data Rate". Also, they are physically different, A DDR modules has one notch on the contact strip, SD modules have two"

And SD-RAM stands for "Synchronized Dynamic-Random Access Memory" which is the typical memory found in Penitum 2's, 3's and some lower end 4's

Answered by Nisha Gill , an ibibo Citizen, at 8:57 PM on October 24, 2008

SDRAM stands for Synchronous Dynamic Random Access Memory. DDR is short for "DDR SDRAM" and stands for Double Data Rate. Nowadays to avoid misunderstandings SDRAM is often specified as SDR SDRAM and SDR stands for Single Data Rate by analogy with DDR. Therefore, the main difference between SDR and DDR memory the doubled speed: DDR can transfer data at roughly twice the speed of SDRAM. For example, PC133 SDRAM runs at 133 Mhz, while 133 Mhz DDR effectively runs at 133 Mhz x 2 = 266 Mhz.

SDRAM has 168 pins and two notches at the connector, which prevents it from being used in a DDR SDRAM motherboard and vice versa. It comes mainly in PC66, PC100 and PC133; the bus speeds of the RAM in MHz.

DDR SDRAM has 184 pins and a single notch at the connector. It comes in speeds of PC1600 (166 MHz), PC1800 (200 MHz), PC2100 (266 MHz), PC2700 (333 MHz), PC3200 (400 MHz), and PC4400 (550 Mhz). The numbers represent the theoretical maximum bandwidth of the DDR SDRAM in Megabytes per second (MB/s). For example, PC2100 has a theoretical maximum bandwidth of 2100 MB/s.
http://wiki.answers.com/Q/Wh at_is_the_difference_between_S DRAM_and_DDR_RAM

Answered by Nishu's , an ibibo Master, at 12:58 PM on October 24, 2008

SDRAM stands for Synchronous Dynamic Random Access Memory. DDR is short for "DDR SDRAM" and stands for Double Data Rate. Nowadays to avoid misunderstandings SDRAM is often specified as SDR SDRAM and SDR stands for Single Data Rate by analogy with DDR. Therefore, the main difference between SDR and DDR memory the doubled speed: DDR can transfer data at roughly twice the speed of SDRAM. For example, PC133 SDRAM runs at 133 Mhz, while 133 Mhz DDR effectively runs at 133 Mhz x 2 = 266 Mhz.

SDRAM has 168 pins and two notches at the connector, which prevents it from being used in a DDR SDRAM motherboard and vice versa. It comes mainly in PC66, PC100 and PC133; the bus speeds of the RAM in MHz.

DDR SDRAM has 184 pins and a single notch at the connector. It comes in speeds of PC1600 (166 MHz), PC1800 (200 MHz), PC2100 (266 MHz), PC2700 (333 MHz), PC3200 (400 MHz), and PC4400 (550 Mhz). The numbers represent the theoretical maximum bandwidth of the DDR SDRAM in Megabytes per second (MB/s). For example, PC2100 has a theoretical maximum bandwidth of 2100 MB/s.

Answered by Sandeep , an ibibo Citizen, at 2:01 PM on October 23, 2008

SDRAM refers to synchronous dynamic random access memory, a term that is used to describe dynamic random access memory that has a synchronous interface. Traditionally, dynamic random access memory (DRAM) has an asynchronous interface which means that it responds as quickly as possible to changes in control inputs. SDRAM has a synchronous interface, meaning that it waits for a clock signal before responding to control inputs and is therefore synchronized with the computer's system bus. The clock is used to drive an internal finite state machine that pipelines incoming instructions. This allows the chip to have a more complex pattern of operation than asynchronous DRAM which does not have a synchronized interface.
Pipelining means that the chip can accept a new instruction before it has finished processing the previous one. In a pipelined write, the write command can be immediately followed by another instruction without waiting for the data to be written to the memory array. In a pipelined read, the requested data appears after a fixed number of clock pulses after the read instruction, cycles during which additional instructions can be sent. (This delay is called the latency and is an important parameter to consider when purchasing SDRAM for a computer.)
DDR SDRAM (double data rate synchronous dynamic random access memory) is a class of memory integrated circuit used in computers. It achieves nearly twice the bandwidth of the preceding [single data rate] SDRAM by double pumping (transferring data on the rising and falling edges of the clock signal) without increasing the clock frequency.
With data being transferred 64 bits at a time, DDR SDRAM gives a transfer rate of (memory bus clock rate) × 2 (for dual rate) × 64 (number of bits transferred) / 8 (number of bits/byte). Thus with a bus frequency of 100 MHz, DDR SDRAM gives a maximum transfer rate of 1600 MB/s.
JEDEC has set standards for speeds of DDR SDRAM, divided into two parts: The first specification is for memory chips and the second is for memory modules. As DDR-SDRAM is superseded by the newer DDR2 SDRAM, the older version is sometimes referred to as DDR1-SDRAM.

Answered by ani , an ibibo Advisor, at 9:59 PM on October 22, 2008

SD Ram is actually SDR SDRAM, and DD Ram is actually DDR SDRAM, though the former does not usually have the SDR in front of it. The letters SDR and DDR stand for Single Data Rate and Double Data Rate, and the letters SDRAM stand for Synchronous Dynamic Random Access Memory.
The main difference between SDR and DDR memory is speed. There are a lot of little differences, but the main one (IMHO) that affects the user is speed: DDR can transfer data at roughly twice the speed of SDR. More speedy data rates = better performance.
Just remember, the motherboard you are using must include the appropriate chipset to support the different RAM types. They are not interchangeable.
SDR SDRAM comes in three main flavors: PC66, PC100 and PC133. Each successive number refers to the bus speed of the RAM in MHz, thus PC66 runs at 66 MHz, PC100 runs at 100 MHz, etc. SDR SDRAM has 168 pins at the connector.
DDR SDRAM has 184 pins at the connector, which is one reason you can't just use DDR instead of SDR, and comes in many different flavors; PC2100 which runs at 266 MHz, PC2700 which runs at 333 MHz, PC3200 which runs at 400 MHz, etc. In order to know which type of RAM you need, you must know what your motherboard supports.
• While the numbers on SDR SDRAM referred to clock speeds, the DDR SDRAM numbers come from the theoretical maximum bandwidth in Megabytes per second (MB/s). Thus, PC2100 has a theoretical maximum bandwidth of 2100 MB/s, but runs at 133 MHz. DDR SDRAM modules are available from PC1600 all the way up to PC4400 now, which has a bandwidth of 4400 MB/s and runs at 550 MHz

Answered by Gyan Singh , an ibibo Master, at 8:48 PM on October 22, 2008

SDRAM refers to synchronous dynamic random access memory, a term that is used to describe dynamic random access memory that has a synchronous interface, meaning that it waits for a clock signal before responding to control inputs and is therefore synchronized with the computer's system bus. Originally simply known as "SDRAM", Single Data Rate SDRAM can accept one command and transfer one word of data per clock cycle. Typical clock frequencies are 100 and 133 MHz. Chips are made with a variety of data bus sizes (most commonly 4, 8 or 16 bits), but chips are generally assembled into 168-pin DIMMs that read or write 64 (non-ECC) or 72 (ECC) bits at a time.

Whereas DDR SDRAM (double data rate synchronous dynamic random access memory) achieves nearly twice the bandwidth of the preceding [single data rate] SDRAM by double pumping (transferring data on the rising and falling edges of the clock signal) without increasing the clock frequency. With data being transferred 64 bits at a time, DDR SDRAM gives a transfer rate of (memory bus clock rate) × 2 (for dual rate) × 64 (number of bits transferred) / 8 (number of bits/byte). Thus with a bus frequency of 100 MHz, DDR SDRAM gives a maximum transfer rate of 1600 MB/s. DDR SDRAM for desktop computers DIMMs have 184 pins (as opposed to 168 pins on SDRAM, or 240 pins on DDR2 SDRAM), and can be differentiated from SDRAM DIMMs by the number of notches (DDR SDRAM has one, SDRAM has two).

As of 2007, 168-pin SDRAM DIMMs are not used in new PC systems, and 184-pin DDR memory has been mostly superseded. DDR2 SDRAM is the most common type used with new PCs, and DDR3 motherboards and memory are widely available, but more expensive than still-popular DDR2 products.

For more extensive details on these memory types, refer to:

http://en.wikipedia.org/wiki /SDRAM (and) http://en.wikipedia.org/wiki/DDR_SD RAM

Answered by Karthick AR , an ibibo Master, at 8:22 PM on October 22, 2008

SDRAM stands for Synchronous Dynamic Random Access Memory. DDR is short for "DDR SDRAM" and stands for Double Data Rate. Nowadays to avoid misunderstandings SDRAM is often specified as SDR SDRAM and SDR stands for Single Data Rate by analogy with DDR. Therefore, the main difference between SDR and DDR memory the doubled speed: DDR can transfer data at roughly twice the speed of SDRAM. For example, PC133 SDRAM runs at 133 Mhz, while 133 Mhz DDR effectively runs at 133 Mhz x 2 = 266 Mhz.

SDRAM has 168 pins and two notches at the connector, which prevents it from being used in a DDR SDRAM motherboard and vice versa. It comes mainly in PC66, PC100 and PC133; the bus speeds of the RAM in MHz.

DDR SDRAM has 184 pins and a single notch at the connector. It comes in speeds of PC1600 (166 MHz), PC1800 (200 MHz), PC2100 (266 MHz), PC2700 (333 MHz), PC3200 (400 MHz), and PC4400 (550 Mhz). The numbers represent the theoretical maximum bandwidth of the DDR SDRAM in Megabytes per second (MB/s). For example, PC2100 has a theoretical maximum bandwidth of 2100 MB/s.

Answered by Alok , an ibibo Citizen, at 6:32 PM on October 22, 2008

Let's start with DRAM. Dynamic Random Access Memory is used to temporarily store information on computers. DRAM is made up of many cells and each cell is referred to as a bit. A cell contains a capacitor and a transistor. Since computer machine language is made up of 1s and 0s, it has the value of one when active and zero when inactive.

SDRAM or Synchronous Random Access Memory is the result of DRAM evolution. This type of memory synchronizes the input and output signals with the system board. Its speed ratings are in MHz. SDRAM was introduced in 1996 and is still used today. SDRAM transmits every clock count at a specific time.

DDR RAM (or Double Data Rate Random Access Memory) does the same but it does so twice every clock count. This makes DDR RAM twice as fast as SDRAM. Over the years, RAM has become very fast and efficient -- and it will be exciting to see what's coming next.

Answered by Koushik , an ibibo Specialist, at 6:11 PM on October 22, 2008

SDRAM stands for Synchronous Dynamic Random Access Memory. DDR is short for "DDR SDRAM" and stands for Double Data Rate. Nowadays to avoid misunderstandings SDRAM is often specified as SDR SDRAM and SDR stands for Single Data Rate by analogy with DDR. Therefore, the main difference between SDR and DDR memory the doubled speed: DDR can transfer data at roughly twice the speed of SDRAM. For example, PC133 SDRAM runs at 133 Mhz, while 133 Mhz DDR effectively runs at 133 Mhz x 2 = 266 Mhz.

SDRAM has 168 pins and two notches at the connector, which prevents it from being used in a DDR SDRAM motherboard and vice versa. It comes mainly in PC66, PC100 and PC133; the bus speeds of the RAM in MHz.

DDR SDRAM has 184 pins and a single notch at the connector. It comes in speeds of PC1600 (166 MHz), PC1800 (200 MHz), PC2100 (266 MHz), PC2700 (333 MHz), PC3200 (400 MHz), and PC4400 (550 Mhz). The numbers represent the theoretical maximum bandwidth of the DDR SDRAM in Megabytes per second (MB/s). For example, PC2100 has a theoretical maximum bandwidth of 2100 MB/s.

Answered by M P , an ibibo Master, at 6:02 PM on October 22, 2008