GDDR 3 (Graphics Double Data Rate, version 3) is a specific RAM memory technology for graphics cards created by ATI Technologies in collaboration with JEDEC . This technology has the same technological base as DDR2 , but considerably reduces consumption and dissipation costs, allowing to increase the efficiency of the modules notably using simple cooling systems. It should be noted that GDDR3 technology is not related to the JEDEC DDR3 specification . This type of memory uses internal terminators, allowing them to manage the data flow of the graphic processes and they are able to work with 4 bits per cycle (as inDDR2 ), that is, 2 bits in each direction in the same cycle, substantially improving bandwidth. The GDDR3 interface transfers two 32 – bit words per clock cycle.
Despite having been designed by ATI , the first graphics card to use this technology was the GeForce FX 5700 Ultra from nVidia , where the DDR2 modules that had been installed until then were replaced . ATI would not start using it until its Radeon X800 range. GDDR3 has been chosen by Sony in the graphics engine of its console PlayStation 3 and Xbox 360 from Microsoft also incorporates 512 MB of this memory. GDDR3 memory is currently being replaced by GDDR5 in higher performance graphics cards, currently in ATI cardsand in the future on cards based on the nVidia GF100 chip . GDDR3 modules currently support a maximum capacity of 1GB and operate between 166 and 800MHz.
