Search results
Results From The WOW.Com Content Network
DDR SDRAM operating with a 100 MHz clock is called DDR-200 (after its 200 MT/s data transfer rate), and a 64-bit (8-byte) wide DIMM operated at that data rate is called PC-1600, after its 1600 MB/s peak (theoretical) bandwidth. Likewise, 12.8 GB/s transfer rate DDR3-1600 is called PC3-12800. Some examples of popular designations of DDR modules:
The name "double data rate" refers to the fact that a DDR SDRAM with a certain clock frequency achieves nearly twice the bandwidth of a SDR SDRAM running at the same clock frequency, due to this double pumping. With data being transferred 64 bits at a time, DDR SDRAM gives a transfer rate (in bytes/s) of (memory bus clock rate) × 2 (for dual ...
Thus with a memory clock frequency of 100 MHz, DDR3 SDRAM gives a maximum transfer rate of 6400 MB/s. The data rate (in MT/s) is twice the I/O bus clock (in MHz) due to the double data rate of DDR memory. As explained above, the bandwidth in MB/s is the data rate multiplied by eight.
Single data rate SDRAM has a single 10-bit programmable mode register. Later double-data-rate SDRAM standards add additional mode registers, addressed using the bank address pins. For SDR SDRAM, the bank address pins and address lines A10 and above are ignored, but should be zero during a mode register write.
Double data rate SDRAM (DDR SDRAM or DDR) was a later development of SDRAM, used in PC memory beginning in 2000. Subsequent versions are numbered sequentially (DDR2, DDR3, etc.). DDR SDRAM internally performs double-width accesses at the clock rate, and uses a double data rate interface to transfer one half on each clock edge. DDR2 and DDR3 ...
Double Data Rate 4 Synchronous Dynamic Random-Access Memory (DDR4 SDRAM) is a type of synchronous dynamic random-access memory with a high bandwidth ("double data rate") interface. Released to the market in 2014, [ 2 ] [ 3 ] [ 4 ] it is a variant of dynamic random-access memory (DRAM), some of which have been in use since the early 1970s, [ 5 ...
Double Data Rate 5 Synchronous Dynamic Random-Access Memory (DDR5 SDRAM) is a type of synchronous dynamic random-access memory. Compared to its predecessor DDR4 SDRAM, DDR5 was planned to reduce power consumption, while doubling bandwidth. [5] The standard, originally targeted for 2018, [6] was released on July 14, 2020. [2]
What determines absolute latency (and thus system performance) is determined by both the timings and the memory clock frequency. When translating memory timings into actual latency, timings are in units of clock cycles, which for double data rate memory is half the speed of the commonly quoted transfer rate. Without knowing the clock frequency ...