At Samsung Tech Day 2022,
Samsung announced GDDR7 as the successor of
GDDR6X, which could deliver up to 36 GT/s.[1] Samsung later announced two months later that it would use
PAM-3 signaling to achieve the highest transfer rate.[2]
On March 8, 2023,
Cadence announced the verification solution tool for preliminary GDDR7
SDRAM production.[3]
On June 30, 2023,
Micron announced that it will be manufactured using 1ß node (equivalent to
12–10 nm process node), slated to release in H1 2024.[4]
On July 18, 2023, Samsung announced the first generation of GDDR7, which can reach up to 32 Gbps per pin (33% higher bandwidth per pin compared to 24 Gbps per pin on GDDR6), 40% higher bandwidth (1.5 TB/s) compared to GDDR6 (1.1 TB/s) and 20% more energy efficient. For packaging material, it will use
epoxy molding compound (EMC) along with
IC architecture optimization, which will reduce thermal resistance by 70%.[5] Later, on a Q&A session, Samsung mentioned that it will be manufactured using D1z node (equivalent to
15–14 nm[6]) and will operate on 1.2V. A 1.1V version with reduced clockspeeds will also be made available at some point in to the future after the release of the 1.2V version.[7]
On March 5, 2024, JEDEC published the GDDR7 Graphics Memory Standard officially and publicly.[8]
Technologies
GDDR7 SDRAM introduced PAM-3 signaling (3 level
pulse-amplitude modulation) instead of
NRZ. PAM-3 is 20% more energy-efficient than NRZ with a higher bandwidth and has lower equipment requirements than PAM-4, making it cheaper. PAM-3 is using 1.58 bits per cycle, while NRZ uses only 1 bit per cycle.[9] GDDR7 SDRAM also will be manufactured using 1ß node (equivalent to 12–10 nm process node), which will be the last
DRAM production process that will rely on
deep ultraviolet (DUV) lithography tools.