Hot, synchronous DRAM: Next-gen memory tech spec DDR5 lands

Power-sipping, phat bandwidth and dope density

Great news for anyone who wants to use Slack and Google Chrome simultaneously: The JEDEC Solid State Technology Association has formalised the spec for DDR5 SDRAM, expected to become the standard memory for most computing devices.

As expected, the new standard promises improved memory density and frequencies, and should speed memory access for multi-core CPUs.

Base data rates are doubled, with DDR4 SDRAM sticks hovering at 1,600 to 3,200 MTps, while the new DDR5 spec offers anywhere between 3,200 to 6,400. Meanwhile, burst length is doubled from eight to 16.

Similarly, density gets a boost. The DDR4 spec caps module capacity at 16GB, for a total of 32GB in a UDIMM. The JDEC DDR5 spec, however, allows module of 64GB, for a max UDIMM size of 128GB. And with support for die-stacking, vendors will be able to push that further up to a theoretical limit of 4TB.

The first DDR5 products will likely be aimed at enterprise and server customers. And it’s not uncommon for enterprise iron to support 2TB of RAM and beyond. As a result, the new DDR5 spec comes with lower power requirements — from 1.2V to 1.1V - paired with a power regulator. By itself, this isn't necessarily groundbreaking, but will undoubtedly add up when DDR5 SDRAM is deployed at scale.

Anyone looking to upgrade to DDR5 will also have to get a new motherboard. While it uses the same number of pins (288) as DDR4, the layout is different. This shouldn’t come as a surprise, however, as all generations of DDR RAM are mutually incompatible. The latest generation merely continues that tradition.

According to slides leaked last year, chipset support for DDR5 will land on Chipzilla’s Sapphire Rapids microarchitecture Intel Xeon processors, along with PCI 5.0 compatibility. This will see a release in 2021, as part of the firm’s Eagle Stream server platform.

Meanwhile, AMD is expected to introduce support around the same time with the release of its Genoa chips. Genoa will use AMD’s upcoming Zen 4 microarchitecture, and like Sapphire Rapids, will target the data center and server markets.

Consumer support for DDR5 SDRAM will likely swiftly follow — although it's not clear exactly when. ®