GDDR, which is short for graphics double data rate, is a type of memory tailored for use with video cards. While it shares design similarities with the DDR SDRAM used as system memory, it is important to note that GDDR has several distinctions that make its performance much faster. These differences, as well as the several versions of GDDR, are listed in the following sections.
Differences between GDDR and DDR
- GDDR is built for much higher bandwidth, thanks to a wider memory bus.
- GDDR1 sends 16 data bits compared to DDR1's 9 bits.
- GDDR can request and receive data on the same clock cycle, DDR cannot.
- GDDR uses less power and gives off less heat, which allows for higher performance modules with simpler cooling systems.
- GDDR3 commonly uses between a 256 and 512-bit bus spread across 4-8 channels whereas DDR1, DDR2, and DDR3 have a 64-bit bus (or 128-bit in dual channel).
Different versions of GDDR