The JEDEC Solid State Storage Association has officially announced the release of JES239 Graphics Double Data Rate 7, the standard for GDDR7 memory, which delivers twice the bandwidth of GDDR6 to 192 GB s to meet the growing demand for high-memory bandwidth for future graphics, gaming, computing, networking, and AI applications.
The JES239 GDDR7 is the first JEDEC standard DRAM to use a pulse amplitude modulation (PAM) interface for high-frequency operation. The PAM3 interface increases the signal-to-noise ratio (SNR) at high frequencies while improving energy efficiency, transmitting 3 bits in 2 cycles by using 3 levels (+1,0,-1), which is stronger than traditional NRZ (non-return-to-zero) interfaces. With the support of PAM3, it can provide a higher data transfer rate per cycle, significantly improving the performance of video memory.
In addition, the JES239 GDDR7 has the following advanced features:
A core-independent LFSR (Linear Feedback Shift Register) training mode that supports eye masking and error counters improves training accuracy while reducing training time.
The number of independent channels has been doubled from 2 to 4 in GDDR6.
Supports 16 Gbit to 32 Gbit memory capacities as well as dual-channel mode to double system capacity.
Meet the market's demand for RAS (Reliability, Availability, Serviceability) by incorporating the latest data integrity features, including on-chip ECC with real-time reporting (ODECC), data poisoning, error checking and cleanup, and command address parity (CAPARBLK) with command blocking.
"The JESD239 GDDR7 marks a significant step forward in high-speed memory design," said Mian Quddus, Chairman of the Board of Directors of JEDEC. With the shift to PAM3 signaling, the memory industry has a new way to extend the performance of GDDR devices, effectively driving the continuous development of high-performance applications. ”
A number of storage manufacturers, including Micron, Samsung, and Hynix, have expressed support for the JES239 GDDR7 standard released by JEDEC and are actively promoting the development plan of GDDR7 video memory. Previously, these three manufacturers have officially announced that they are preparing new GDDR7 video memory, of which Samsung's first 16GB GDDR7 chip provides up to 1536 TBS of bandwidth, far more than the current GeForce RTX 4090 by 1008 tb/s。The GDDR7 memory chip displayed by SK hynix has a speed of 354Gbps, slightly slower than the speed announced by Samsung. Micron has not released relevant details.