Rambus releases GDDR7 Memory Controller IP

In March of this year, the JEDEC Solid State Technology Association formally introduced the JES239 Graphics Double Data Rate 7, or GDDR7 standard, which offers double the bandwidth of GDDR6, reaching an impressive 192 GB/s. This development is aimed at meeting the growing demands for high memory bandwidth in future applications across graphics, gaming, computing, networking, and artificial intelligence (AI). Notably, Samsung had already completed the development of the industry’s first GDDR7 chip as early as July last year, achieving a rate of 32Gbps per data I/O interface.

Recently, Rambus announced the launch of its GDDR7 controller IP, a memory solution tailored for AI 2.0. This product is part of a leading portfolio of interface and security digital IP products and is already on the market. Rambus claims that this new GDDR7 controller IP will provide the breakthrough memory throughput required for the next wave of AI inference, serving both servers and clients with a fully featured, bandwidth-efficient solution.

Key features of the Rambus GDDR7 controller include:

• Support for all GDDR7 link functions, including PAM3 and NRZ signaling.
• Compatibility with various GDDR7 device sizes and speeds.
• Optimization for efficiency and low latency across different traffic scenarios.
• Flexible AXI interface support.
• Low power consumption features, such as self-refresh, sleep self-refresh, and dynamic frequency scaling.
• Reliability, Availability, and Serviceability (RAS) features, such as end-to-end data path parity and register parity protection.
• Comprehensive memory testing support.
• Integration support for third-party PHYs.
• Validation using the latest GDDR7 VIP and memory models from memory suppliers.

Unlike the NRZ/PAM2 used in existing GDDR6 or the PAM4 signaling in GDDT6X, GDDR7 utilizes a PAM3 signaling mechanism. NRZ/PAM2 transmits one bit per cycle, PAM4 transmits two bits per cycle, and PAM3 results in three bits transmitted every two cycles.

Rambus states that this new GDDR7 controller IP is ideal for cutting-edge AI accelerators, graphics, and high-performance computing (HPC) applications. It supports operations at 40 Gbps, providing a throughput of 160 GB/s for GDDR7 memory devices. This represents a 67% increase over the industry’s highest throughput GDDR6 controllers, fully accommodating the deployment of the next generation of GDDR memory.