What We Know About DDR5 So Far

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Double Data Rate 5 (DDR5) is the next-generation standard for random-access memory (RAM). The new specification promises to bring chips that have much higher performance than the existing DDR4 modules, as well as lower power consumption. But what does that mean for desktop PCs? Let's take a look at what we know so far.

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Lucian Armasu
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Lucian Armasu is a Contributing Writer for Tom's Hardware US. He covers software news and the issues surrounding privacy and security.

13 Comments Comment from the forums
  • TJ Hooker
    Lucian Armasu said:
    DDR5-3200 RAM will see an increase of 1.36x in bandwidth compared to DDR4-3200. However, DRAM chips are expected to ship with a bandwidth of 4800MT/s, or 1.87x that of DDR4-3200 RAM.
    The DDR5 RAM chips are expected to start at 4800MT/s, which would be a 1.87x increase in bandwidth compared to DDR4-3200 RAM. The DDR5 standard has an official limit of 6400MT/s, but we may see some memory companies push that further.
    All other information I've seen indicates that the only source of increased bandwidth for DDR5 is from increased transfer rate, such that if DDR5 and DDR4 were running at same speed they'd have the same bandwidth. As has been the case going back all the way to the original DDR SDRAM. Is there just lots of typos/bad math in this article, or is there some other factor increasing the bandwidth of DDR5 compared to DDR4 other than transfer rate?
    Reply
  • XaveT
    <nit-picky>
    The article has some repeated text, can we get a bit of a clean-up? I only mention it because it was distracting trying to read through it.
    </nit-picky>
    Reply
  • Xajel
    TJ Hooker said:
    All other information I've seen indicates that the only source of increased bandwidth for DDR5 is from increased transfer rate, such that if DDR5 and DDR4 were running at same speed they'd have the same bandwidth. As has been the case going back all the way to the original DDR SDRAM. Is there just lots of typos/bad math in this article, or is there some other factor increasing the bandwidth of DDR5 compared to DDR4 other than transfer rate?

    DDR5 is rumoured to have 16n prefetch mode, which if it happens means at the same clock DDR5 should be twice as fast as DDR4.

    It's the same as what DDR3 brought compared to DDR2 which also doubled it compared to DDR.

    DDR3 and DDR4 both had 8n prefetch, DDR5 is still unconfirmed, some says it has 8n like DDR3 & 4. While some says it has 16n, like GDDR5 & HBM2.
    Reply
  • jimmysmitty
    A 32GB stick of DDR5 RAM should have the same density as a 16GB DDR4 stick while delivering roughly twice the performance.

    This line doesn't make any sense. If a it is a 32GB stick, although a different pin layout most likely, it is twice a s dense as a 16GB DDR4 stick.

    Now if you are talking about the number of DRAM modules on the stick then I could see it being true if its has 16 per stick (8 per side).
    Reply
  • Paul Alcorn
    TJ Hooker said:
    All other information I've seen indicates that the only source of increased bandwidth for DDR5 is from increased transfer rate, such that if DDR5 and DDR4 were running at same speed they'd have the same bandwidth. As has been the case going back all the way to the original DDR SDRAM. Is there just lots of typos/bad math in this article, or is there some other factor increasing the bandwidth of DDR5 compared to DDR4 other than transfer rate?

    Here's a bit more info on the matter 1116168728046002176View: https://twitter.com/david_schor/status/1116168728046002176
    Reply
  • TJ Hooker
    Xajel said:
    DDR5 is rumoured to have 16n prefetch mode, which if it happens means at the same clock DDR5 should be twice as fast as DDR4.

    It's the same as what DDR3 brought compared to DDR2 which also doubled it compared to DDR.

    DDR3 and DDR4 both had 8n prefetch, DDR5 is still unconfirmed, some says it has 8n like DDR3 & 4. While some says it has 16n, like GDDR5 & HBM2.
    This doesn't really make sense either. If doubling prefetch doubled bandwidth for the same transfer rate, why does DDR2 have the same bandwidth as DDR if they're both running at the same speed? Same for DDR3 vs DDR2. Same for GDDR5X vs GDDR5. Also, even if increasing prefetch did increase bandwidth at the same transfer rate, according to the article DDR5 only has 36% more bandwidth than DDR4 at the same transfer rate, not 100%:
    DDR5-3200 RAM will see an increase of 1.36x in bandwidth compared to DDR4-3200.

    Edit: I should clarify that when I say bandwidth I'm talking about theoretical max bandwidth.
    Reply
  • vaughn2k
    In March 2017, JEDEC, the group developing the DDR standard as well as other memory and storage standards, announced that it would release the DDR5 specification in 2018
    This is from the JEDEC Specification JESD21-C Configurations for Solid State Memories maintained by JC41 JEDEC Committee - which is also the committee developing the DDR standard.
    JEDEC Organization, as a whole, is not only responsible for memory standard, but all semiconductor, and microelectronics standardization for interoperability.
    Reply
  • epobirs
    The next generation of Sony and Microsoft game consoles will be likely early adopters. It's already been well demonstrated how big a difference memory performance makes for AMD Ryzen APUs gaming performance. Unless the cost makes it out of bounds, having DD5 or comparable GDDR generation is the kind of bleeding edge item expected of a console at launch that becomes run of the mill for PCs within a year or so. Unless they go for an HBM setup, which could lend itself well to console needs.
    Reply
  • delaro
    Back to $260+ RAM Sticks. :ROFLMAO:
    Reply
  • JamesSneed
    With higher memory densities of 32GB per module that are out now couldn't AMD/Intel make triple channel controllers standard for desktop parts? Having a max of 96GB doesn't seem all that limiting in a non HEDT platform. It would increase cost a bit for the extra pins but it should provide enough bandwidth even on DDR4 for 12-20 cores.
    Reply