Engineering:GDDR SDRAM

Short description: Type of memory used on graphics cards

Graphics DDR SDRAM (GDDR SDRAM) is a type of synchronous dynamic random-access memory (SDRAM) specifically designed for graphics processing units (GPUs). GDDR SDRAM is distinct from the more widely known types of DDR SDRAM, such as DDR4, although they share some of the same features—including double data rate data transfers. (As of 2018), GDDR SDRAM has been succeeded by GDDR2, GDDR3, GDDR4, GDDR5, GDDR5X, GDDR6, and GDDR6X.

Generations

• 

  Hynix GDDR SDRAM

• 

  A Samsung GDDR3 256MBit package

• 

  A 512 MBit Qimonda GDDR3 SDRAM package

• 

  Inside a Samsung GDDR3 256MBit package

DDR SGRAM

GDDR was initially known as DDR SGRAM (double data rate synchronous graphics RAM). It was commercially introduced as a 16 Mb memory chip by Samsung Electronics in 1998.

GDDR2

Main article: DDR2 SDRAM

Table of transfer rates

Module type	Chip type	Memory clock	Transfers/s	Transfer rate
?	GDDR2	500 MHz	?	128 Gbit/s	16.0 GB/s
64 lanes	GDDR3	625 MHz	2.5 GT/s	159 Gbit/s	19.9 GB/s
64 lanes	GDDR4	275 MHz	2.2 GT/s	140.8 Gbit/s	17.6 GB/s
64 lanes	GDDR5	625–1000 MHz	5–8 GT/s	320–512 Gbit/s	40–64 GB/s
64 lanes	GDDR5X	625–875 MHz	10–12 GT/s	640–896 Gbit/s	80–112 GB/s
64 lanes	GDDR6	875–1000 MHz	14–16 GT/s	896–1024 Gbit/s	112–128 GB/s
64 lanes	GDDR6X

See also

• Double data rate