GDDR7

Overview#

GDDR7 is JEDEC's seventh-generation graphics memory standard, ratified in March 2024. It moves from NRZ (GDDR6) and PAM4 (GDDR6X) to PAM3 — a three-level signalling scheme — that offers better bandwidth-per-watt than PAM4 while sidestepping some of GDDR6X's equalisation complexity.

Launch deployments include NVIDIA's RTX 50-series consumer GPUs and various workstation and embedded parts. As a JEDEC standard it is supported by multiple DRAM vendors (Samsung, Micron, SK hynix), unlike GDDR6X.

Specifications#

Architecture Notes#

PAM3 transmits 1.5 bits per cycle effectively, occupying a middle ground between NRZ (1 bit/cycle) and PAM4 (2 bits/cycle). The result is better signal margin than PAM4 at higher symbol rates than NRZ, with substantially improved bandwidth-per-watt characteristics.

JEDEC standardisation matters operationally: GDDR7 controllers, training algorithms and PHYs are multi-vendor, easing supply diversification compared to GDDR6X.

Where GDDR7 Matters#

• Consumer and prosumer GPUs (RTX 50-series and successors).
• Workstation cards needing high bandwidth without HBM cost.
• Embedded AI accelerators and edge inference cards.
• For data centre training — HBM remains the preferred memory.

Pitfalls#

• PAM3 controllers are newer and less mature than the GDDR6 stack — early production may show variance.
• Bandwidth still trails HBM3e by significant margins.
• Multi-card configurations without NVLink remain PCIe-bound.