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Ddr5 sdram

The meaning of «ddr5 sdram»

Double Data Rate 5 Synchronous Dynamic Random-Access Memory (DDR5 SDRAM) is a type of synchronous dynamic random-access memory. Compared to its predecessor DDR4 SDRAM, DDR5 is planned to reduce power consumption, while doubling bandwidth.[2] The standard, originally targeted for 2018,[3] was released on 14 July 2020.[1]

A new feature called Decision Feedback Equalization (DFE) enables IO speed scalability for higher bandwidth and performance improvement. DDR5 supports more bandwidth than its predecessor, DDR4, with 4.8 gigabits per second possible — but not shipping at launch.[4] DDR5 will have about the same latency as DDR4 and DDR3.[5]

Rambus announced a working DDR5 DIMM in September 2017.[6][7] On November 15, 2018, SK Hynix announced completion of its first DDR5 RAM chip; it runs at 5200 MT/s at 1.1 V.[8] In February 2019, SK Hynix announced a 6400 MT/s chip, the highest speed officially allowed by the preliminary DDR5 standard.[9] Some companies were planning to bring the first products to market by the end of 2019.[10] The world's first DDR5 DRAM chip was officially launched by SK Hynix on October 6th, 2020.[11][12]

The separate JEDEC standard LP-DDR5 (Low Power Double Data Rate 5), intended for laptops and smartphones, was released in February 2019.[13]

Compared to DDR4, DDR5 further reduces memory voltage to 1.1 V, thus reducing power consumption. DDR5 modules can incorporate on-board voltage regulators in order to reach higher speeds; but as this will increase cost, it is expected to be implemented only on server-grade and possibly high-end consumer modules.[7] DDR5 supports a speed of 51.2 GB/s per module[14] and 2 memory channels per module.[15][16]

There is a general expectation that most use-cases that currently use DDR4 will eventually migrate to DDR5. To be usable in desktops and servers (laptops will presumably use LP-DDR5 instead), the integrated memory controllers of e.g. Intel's and AMD's CPUs will have to support it; as of June 2020, there have not been any official announcements of support from either. Intel’s 11th-gen Rocket Lake CPUs and AMD's Ryzen 5000-series CPUs both still use DDR4 RAM.[17] A leaked internal AMD roadmap is reported to show DDR5 support for 2022 Zen 4 CPUs and Zen 3+ APUs.[18] A leaked slide shows planned DDR5 support on Intel's 2021 Sapphire Rapids microarchitecture and Alder Lake microarchitecture.[19]

While previous SDRAM generations allowed unbuffered DIMMs that consisted of memory chips and passive wiring (plus a small serial presence detect ROM), DDR5 DIMMs require additional active circuitry, making the interface to the DIMM different from the interface to the RAM chips themselves.

DDR5 DIMMs are supplied with bulk power at 1.2 V and management interface power at 3.3 V,[20] and use on-board circuitry (a power management integrated circuit[21] and associated passive components) to convert to the lower voltage required by the memory chips. Final voltage regulation close to the point of use provides more stable power, and mirrors the development of voltage regulator modules for CPU power supplies.

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