| DRAM types |
XDR2 DRAM is a type of Dynamic Random Access Memory that is in development by Rambus. SDRAM refers to synchronous Dynamic random access memory, a term that is used to describe dynamic random access memory that has a synchronous interface SDRAM refers to synchronous Dynamic random access memory, a term that is used to describe dynamic random access memory that has a synchronous interface DDR SDRAM ( double data rate synchronous dynamic random access memory) is a class of memory Integrated circuit used in Computers It achieves nearly twice In Electronic engineering, DDR3 SDRAM or double-data-rate three Synchronous dynamic random access memory is a Random access memory Direct Rambus DRAM or DRDRAM (sometimes just called Rambus DRAM or RDRAM) is a type of synchronous dynamic RAM, designed by the Rambus XDR DRAM or extreme data rate Dynamic random access memory is a high-performance RAM interface and successor to the Rambus RDRAM it V irtual C hannel R andom A ccess M emory ( VC-RAM GDDR3, Graphics Double Data Rate 3, is a graphics card-specific memory technology designed by ATI Technologies with the collaboration of JEDEC GDDR4 SDRAM (Graphics Double Data Rate version 4 is a type of Graphics card memory specified by the JEDEC Semiconductor Memory Standard GDDR5 (Graphics Double Data Rate version 5 is a type of Graphics card memory the standards of which were set out in the GDDR5 specification by JEDEC Rambus Incorporated ( founded in 1990, is a provider of high-speed interface technology most notably their Rambus Dynamic RAM memory technology, which Announced in 2005-7-7 and has been released in March, 26 2008, it is the successor to XDR DRAM. XDR DRAM or extreme data rate Dynamic random access memory is a high-performance RAM interface and successor to the Rambus RDRAM it
XDR2 DRAM is being used in high-end graphics cards and networking equipment. A video card, also known as a graphics accelerator card, display adapter, or graphics card, is a hardware component whose function is to
Contents |
Changes over XDR DRAM
Signaling
The memory chips of XDR2 are targeted to run at 500 MHz, compared to 200 MHz memory chips found in XDR memory. Like XDR DRAM, XDR2 DRAM has data transfer rates at 16 times the memory chips' core clock speed, with signal bus running at 4 times the core clock speed. Combined with the faster memory chips, this results in the data bus running at an effective 8. 0 GHz and the signal bus running at an effective 2. 0 GHz. The XDR2 memory bus uses a Hex Data Rate (HDR) scheme, transferring data on the memory bus at 16 times the rate of the system clock running at 500 MHz.
Micro-threading
Banks within chips are organized into 2 channels, with each channel controlling half of the banks. Within each channel, there are 2 column and row decoders, with each set of row+column decoders addressing 8-bit of data. In 16-bank design, granularity is reduced from 32 bytes to 16 bytes.
External links
- XDR2 DRAM in Rambus Home page
- Rambus Unveils Next Generation XDR(TM) Memory Interface; 8GHz XDR2 DRAM with Micro-Threading Enables Unprecedented Graphics Capabilities
- XDR2 vs DDR3 article (in Chinese)