SDRAM, or synchronous DRAM, is a type of dynamic random-access memory (DRAM) that can be read from or written to by both the CPU and any attached devices at the same time. This allows for much higher bandwidth than would otherwise be possible. The disadvantage to this system is that it requires a clock signal in order to work properly. DDR RAM, on other hand, does not require a clock signal because it can operate asynchronously with respect to the CPU. This makes DDR RAM cheaper but also less efficient when compared with SDRAM.
The clock signal used by SDRAM is provided by a phase-locked loop (PLL), which converts the CPU’s input clock frequency into the much higher frequency needed for SDRAM. This PLL circuit makes it very difficult to develop systems that use both types of RAM, because there are issues with crosstalk and timing skew between them. To avoid these problems, most computers use either one type of memory or another. For example, some computers use DDR2 RAM exclusively while others use only SDRAM.
One exception to this rule is the new form of DRAM known as synchronous graphics RAM (SGRAM). Like its name suggests, this type of memory is designed specifically with graphics cards in mind. However, because many other devices also access the RAM on a graphics card at once, it is designed to be compatible with both SDRAM and DDR RAM.
The differences between SDRAM and DDR RAM
1)Synchronous Dynamic Random-Access Memory(SDRAM) has a clock signal that synchronizes its actions with CPU cycles while Double Data Rate Random Access Memory(DDR-RAM) does not require a clock signal to operate properly
2)Dram is cheaper than sdram
3)DDRRAM can asynchronously with respect to the CPU which makes it cheaper but less efficient compared to SDRAM
4)SDRAM has a clock signal that synchronizes its actions with the CPU cycles.
5)SDRAM is used in most computers. DDR-RAM does not need to use a clock signal because it can operate asynchronously with respect to the CPU.
6)DDR-RAM is more efficient than SDRAM because things can be done at once, instead of one thing after another
7)SGRAM uses both DRR and SDR memory types
8)In order for a computer to have both types of RAM, it must contain separate slots and buses for each type
9)The differences between SD-RAM and DDR-RAM: 1 / 2 sdram uses clock signals while DRAM does not. When using DDR-RAM, you must make sure that both are running off the same frequency to avoid inaccurate reading and writing of information. DDR-RAM is also more efficient than SD-RAM because it can read data at one time instead of one after another.
2 / 2 Both RAM types are compatible with the PCI Slot but require different adapters. For example, if your computer has a slot for SDRAM you will not be able to use it unless there is an adapter or motherboard that allows you to do so. The advantage to having multiple memory slots in a computer is that if one type of RAM fails you have an extra set in place in case yours stops functioning properly in which case you have an insurance policy of sorts.
SDRAM, or synchronous DRAM
SDRAM, or synchronous DRAM, is a type of dynamic random-access memory (DRAM) that can be read from or written to by both the CPU and any attached devices at the same time. This allows for much higher bandwidth than would otherwise be possible. The disadvantage to this system is that it requires a clock signal in order to work properly. DDR RAM, on other hand, does not require a clock signal because it can operate asynchronously with respect to the CPU.
This makes DDR RAM cheaper but also less efficient when compared with SDRAM.To put it simply, SDRAM is a kind of DRAM with a clock signal to synchronize its actions with the CPU’s clock cycle while DDR RAM doesn’t need a clocking signal as long as both the PC and the RAM are running off the same frequency. In terms of efficiency, DDR RAM performs better than SD-RAM because things can be done at once instead of one thing after another.