Graphics Double Data Rate 7 Synchronous Dynamic Random-Access Memory (GDDR7 SDRAM) is a type of
synchronous graphics random-access memory (SGRAM) specified by the
JEDEC
The Joint Electron Device Engineering Council (JEDEC) Solid State Technology Association is a consortium of the semiconductor industry headquartered in Arlington County, Virginia, Arlington, United States. It has over 300 members and is focused ...
Semiconductor Memory Standard, with a high
bandwidth, "
double data rate
In computing, double data rate (DDR) describes a computer bus that transfers data on both the rising and falling edges of the clock signal and hence doubles the memory bandwidth by transferring data twice per clock cycle. This is also known a ...
" interface, designed for use in
graphics cards
A graphics card (also called a video card, display card, graphics accelerator, graphics adapter, VGA card/VGA, video adapter, display adapter, or colloquially GPU) is a computer expansion card that generates a feed of graphics output to a displa ...
,
game consoles, and
high-performance computing
High-performance computing (HPC) is the use of supercomputers and computer clusters to solve advanced computation problems.
Overview
HPC integrates systems administration (including network and security knowledge) and parallel programming into ...
. It is a type of
GDDR SDRAM (graphics
DDR SDRAM
Double Data Rate Synchronous Dynamic Random-Access Memory (DDR SDRAM) is a double data rate (DDR) synchronous dynamic random-access memory (SDRAM) class of memory integrated circuits used in computers. DDR SDRAM, also retroactively called DDR ...
), and is the successor to
GDDR6
Graphics Double Data Rate 6 Synchronous Dynamic Random-Access Memory (GDDR6 SDRAM) is a type of synchronous graphics random-access memory (SGRAM) with a high bandwidth, "double data rate" interface, designed for use in graphics cards, game con ...
.
History
* At Samsung Tech Day 2022,
Samsung
Samsung Group (; stylised as SΛMSUNG) is a South Korean Multinational corporation, multinational manufacturing Conglomerate (company), conglomerate headquartered in the Samsung Town office complex in Seoul. The group consists of numerous a ...
announced GDDR7 as the successor of
GDDR6X
Graphics Double Data Rate 6 Synchronous Dynamic Random-Access Memory (GDDR6 SDRAM) is a type of Synchronous dynamic random-access memory#Synchronous graphics RAM .28SGRAM.29, synchronous graphics random-access memory (SGRAM) with a high Bandwidth ...
, which could deliver up to 36 GT/s. Samsung announced two months later that it would use
PAM-3 signaling to achieve the highest transfer rate.
* On March 8, 2023,
Cadence announced the verification solution tool for preliminary GDDR7
SDRAM
Synchronous dynamic random-access memory (synchronous dynamic RAM or SDRAM) is any DRAM where the operation of its external pin interface is coordinated by an externally supplied clock signal.
DRAM integrated circuits (ICs) produced from the ...
production.
* On June 30, 2023,
Micron
The micrometre (English in the Commonwealth of Nations, Commonwealth English as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American English), also commonly known by the non-SI term micron, is a uni ...
announced that it will be manufactured using 1β node (equivalent to
12–10 nm process node), slated to release in H1 2024.
* On July 18, 2023, Samsung announced the first generation of GDDR7, which can reach up to 32 Gbps per pin (100% higher bandwidth per pin compared to 16 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%. Later, on a Q&A session, Samsung mentioned that it will be manufactured using D1z node (equivalent to
15–14 nm) 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.
* On March 5, 2024, JEDEC published the GDDR7 Graphics Memory formal standard and specifications.
Technologies
GDDR7 SDRAM employs three-level (-1, 0, +1)
pulse-amplitude modulation
Pulse-amplitude modulation (PAM) is a form of signal modulation in which the message information is encoded in the amplitude of a pulse train interrupting the carrier frequency. Demodulation is performed by detecting the amplitude level of th ...
(PAM-3) instead of
NRZ in GDDR6 and PAM-4 in GDDR6x. PAM-3 enables the transfer of three bits of data within two cycles, while NRZ transfer of one bits of data within one cycle. PAM-3 is 20% more energy-efficient than NRZ while running at a higher bandwidth. Manufacturing equipment will be less costly than PAM-4.
GDDR7 adds on-die
error correction code
In computing, telecommunication, information theory, and coding theory, forward error correction (FEC) or channel coding is a technique used for controlling errors in data transmission over unreliable or noisy communication channels.
The centra ...
, error checking and
scrubbing features for chip reliability, mainly useful for compute/
AI use cases.
Initial data rates are at 32Gbps/pin, while memory manufacturers have noted that rates up to 36Gbps/pin are readily attainable. The standard has future bandwidth up to 48Gbps/pin,
and chip capacities up to 64Gbit - compared to GDDR6X's 16Gbit.
See also
*
List of interface bit rates
References
External links
{{DEFAULTSORT:Gddr7
SDRAM