Editing Synchronous dynamic random-access memory (section)

== {{Anchor|SGRAM}}Synchronous Graphics RAM (SGRAM) ==
Synchronous graphics RAM (SGRAM) is a specialized form of SDRAM for graphics adaptors. It is designed for graphics-related tasks such as [[texture memory]] and [[framebuffer]]s, found on [[video card]]s. It adds functions such as [[bit mask]]ing (writing to a specified bit plane without affecting the others) and block write (filling a block of memory with a single colour). Unlike [[Video RAM (dual-ported DRAM)|VRAM]] and [[WRAM (memory)|WRAM]], SGRAM is single-ported. However, it can open two memory pages at once, which simulates the [[Dual-ported RAM|dual-port]] nature of other video RAM technologies.

The earliest known SGRAM memory are 8{{nbsp}}Mbit{{binpre}} chips dating back to 1994: the [[Hitachi]] HM5283206, introduced in November 1994,<ref name="HM5283206"/> and the [[NEC]] μPD481850, introduced in December 1994.<ref name="D481850"/> The earliest known commercial device to use SGRAM is [[Sony]]'s [[PlayStation (console)|PlayStation]] (PS) [[video game console]], starting with the Japanese [[PlayStation models|SCPH-5000]] model released in December 1995, using the NEC μPD481850 chip.<ref>{{cite web |title=PU-18 |url=http://wiki.psxdev.ru/index.php/PU-18 |website=PSXDEV |access-date=10 July 2019}}</ref><ref name="nec1995"/>

=== Graphics double data rate SDRAM (GDDR SDRAM) ===
{{Main|GDDR SDRAM}}

Graphics [[double data rate]] SDRAM ([[GDDR SDRAM]]) is a type of specialized [[DDR SDRAM]] designed to be used as the main memory of [[graphics processing unit]]s (GPUs). GDDR SDRAM is distinct from commodity types of DDR SDRAM such as DDR3, although they share some core technologies. Their primary characteristics are higher clock frequencies for both the DRAM core and I/O interface, which provides greater memory bandwidth for GPUs. As of 2025, there are nine successive generations of GDDR: [[GDDR2]], [[GDDR3]], [[GDDR4]], [[GDDR5]], [[GDDR5X]], [[GDDR6]], [[GDDR6X]], [[GDDR6W]], and [[GDDR7]].

GDDR was initially known as DDR SGRAM. It was commercially introduced as a 16{{nbsp}}[[Megabit|Mbit]]{{binpre}} memory chip by [[Samsung Electronics]] in 1998.<ref name="samsung98"/>