GDDR-III: new DRAM standard for graphics cards

Micron Technology and ATI Technologies representatives said that GDDR-III chips will provide 1-1.5 Gbps linear throughput, almost doubling the performance of DDR-II SDRAM to be yet become the mainstream next year, but is already slow for graphically intensive apps. Therefore, according to ATI, it was decided to unite with DRAM makers and develop GDDR-III open memory standard that might live outside limits, approved by JEDEC Solid State Technology Association.

The main reason for GDDR-III independent development is that graphics card makers can´t wait for two or three years until JEDEC approves the new standard, as after such a period any JEDEC´s DRAM standard might become obsolete. ATI representative has also said that JEDEC does serious and important job for developing PC memory standards, however there´s no need to combine memory modules, chipsets and mobos for graphics memory. Especially, as the system memory standard lasts two to three years, but graphics memory lasts about nine months only.

Industry won´t be forced to use GDDR-III, instead all the leading DRAM makers are taking part in its development and will be able to produce it. Both ATI, and NVIDIA are taking part in GDDR-III development and commercialization as well.

Micron representatives promise to launch GDDR-III volume production already in Q2 2003, Korean Hynix Semiconductor — in H1 2003, Infineon Technologies plans to announce GDDR-III samples in H1 2003 as well to launch volume production later.

Initially GDDR-III are expected to feature 256 Mbit capacity, 500 MHz clock and 1Gbps linear throughtput. Then clocks are to grow up to 750MHz, linear throughtput — up to 1.5Gbps. According to makers, despite GDDR-III specs are based on DDR-II standard, these will be completely different CSP (chip-scale packaging) chips of 144-pin BGA configuration unlike 84-pin DDR-II CSP chips. GDDR-III I/O bus will be formed, using open drain technology (unlike two-cycle I/O bus of PC memory), that will help to achieve high clocks faster and make graphics card design easier. Besides, new graphics memory chips will feature on-die termination (ODT) tied to the open-drain design. Despite both memory types will utilize impedance-matching controllers, GDDR-III will have simpler design due to direct chip connectivity architecture.

By the way, according to specialists, GDDR-III might be used not only in graphics cards, but also in comms and consumer electronics, requiring high-performance memory.

Meanwhile, according to provisional data, JEDEC already works on DDR-III specs of PC. JEDEC sources report that five DRAM makers, including Elpida, Hynix, Infineon, Micron, and Samsung, decided to share main parts of the future standard to develop drafts on their own. First drafts are expected to be joined together at JEDEC quarterly meeting in December.

JEDEC aims DDR-III at achieving 1Gbps and higher linear throughput, however many belive that GDDR-III is to become mainstream before DDR-III final version is released.

Source: EB News

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