View source for Engineering:GDDR SDRAM

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{{Memory types}}
{{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 unit|graphics processing unit]]s (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&mdash;including double data rate data transfers. {{As of|2018}}, GDDR SDRAM has been succeeded by GDDR2, GDDR3, GDDR4, GDDR5, GDDR5X, GDDR6, and GDDR6X.

==Generations==
<gallery mode="packed" heights=100px>
File:ATI Radeon X1300 256MB - Hynix HY5DU561622CTP-5-5390.jpg|thumb|[[Company:SK Hynix|Hynix]] GDDR SDRAM
File:SAMSUNG@QDDR3-SDRAM@256MBit@K5J55323QF-GC16 Stack-DSC01234-DSC01284 - ZS-retouched.jpg|thumb|A Samsung GDDR3 256MBit package
File:Sapphire Ultimate HD 4670 512MB - Qimonda HYB18H512321BF-10-93577.jpg|alt=|thumb|A 512 MBit [[Company:Qimonda|Qimonda]] GDDR3 SDRAM package
File:SAMSUNG@QDDR3-SDRAM@256MBit@K5J55323QF-GC16 Stack-DSC01340-DSC01367 - ZS-retouched.jpg|thumb|Inside a Samsung GDDR3 256MBit package
</gallery>
===DDR SGRAM===
GDDR was initially known as DDR SGRAM (double data rate synchronous graphics RAM). It was commercially introduced as a 16{{nbsp}}[[Mebibit|Mb]] memory chip by [[Company:Samsung Electronics|Samsung Electronics]] in 1998.<ref>{{cite news |title=Samsung Electronics Comes Out with Super-Fast 16M DDR SGRAMs |url=https://www.samsung.com/semiconductor/insights/news-events/samsung-electronics-comes-out-with-super-fast-16m-ddr-sgrams/ |access-date=23 June 2019 |work=[[Company:Samsung Electronics|Samsung Electronics]] |publisher=[[Company:Samsung|Samsung]] |date=17 September 1998}}</ref>

===GDDR2===
Main article: DDR2 SDRAM

===GDDR3===

===GDDR4===

===GDDR5===

===GDDR6===

==Table of transfer rates==
{|class="wikitable sortable"
! Module type !! Chip type !! Memory clock !! Transfers/s !! colspan=2 | Transfer rate
|-
| ? || GDDR2 || align=right| {{val|500|u=MHz}}  ||align=right|  ? ||align=right| {{val|128|u=Gbit/s}}   ||align=right| {{val|16.0|u=GB/s}} <!-- GeForce FX 5800 Ultra -->
|-
|-
| 64 lanes    || GDDR3           ||align=right| {{val|625|u=MHz}}  ||align=right| {{val|2.5|u=GT/s}}  ||align=right| {{val|159|u=Gbit/s}}   ||align=right| {{val|19.9|u=GB/s}} <!-- GF GTX 285 -->
|-
| 64 lanes    || GDDR4           ||align=right| {{val|275|u=MHz}}  ||align=right| {{val|2.2|u=GT/s}}  ||align=right| {{val|140.8|u=Gbit/s}} ||align=right| {{val|17.6|u=GB/s}} <!-- Rd HD 4670 -->
|-
| 64 lanes    || GDDR5<ref>{{Cite web|url=http://www.jedec.org/standards-documents/docs/jesd212c |publisher=JEDEC |title=GRAPHICS DOUBLE DATA RATE (GDDR5) SGRAM STANDARD JESD212C |date=2016-02-01 |access-date=2016-08-10}}</ref>  ||align=right| {{val|625|-|1000|u=MHz}}  ||align=right| {{val|5|-|8|u=GT/s}}    ||align=right| {{val|320|-|512|u=Gbit/s}}   ||align=right| {{val|40|-|64|u=GB/s}}
|-
| 64 lanes    || GDDR5X<ref>{{Cite web|url=http://www.jedec.org/standards-documents/docs/jesd232 |publisher=JEDEC |title=GRAPHICS DOUBLE DATA RATE (GDDR5X) SGRAM STANDARD JESD232 |date=2015-11-01 |access-date=2016-08-10}}</ref>  ||align=right| {{val|625|-|875|u=MHz}}  ||align=right| {{val|10|-|12|u=GT/s}}    ||align=right| {{val|640|-|896|u=Gbit/s}}   ||align=right| {{val|80|-|112|u=GB/s}}
|-
|64 lanes
|GDDR6
|align=right| {{val|875|–|1000|u=MHz}}
|align=right| {{val|14|-|16|u=GT/s}}
|align=right| {{val|896|–|1024|u=Gbit/s}}
|align=right| {{val|112|–|128|u=GB/s}}
|-
|-
|64 lanes
|GDDR6X
|align=right| 
|align=right| 
|align=right| 
|align=right| 
|-
|}

==See also ==
* [[Engineering:Double data rate|Double data rate]]

==References==
{{reflist}}

{{Graphics Processing Unit}}

[[Category:Video cards]]


{{Sourceattribution|GDDR SDRAM|1}}