New DDR5 SDRAM standard supports double the bandwidth of DDR4

Posted:
in General Discussion edited July 2020
JEDEC, the controlling body of the RAM standard, has published details about the DDR5 SDRAM spec to address the demand for ever-faster RAM.

RAM slots on a Mac Mini


The new DDR5 spec is designed to enable scaling memory performance without degrading channel efficiency at higher speeds. This was done by doubling the burst-length to BL16 and bank-count to 32 from 16. DDR5 DIMM also has two 40-bit independent sub-channels, increasing efficiency, and reliability.

A new feature deemed Decision Feedback Equalization (DFE) enables IO speed scalability for higher bandwidth and performance improvement. DDR5 supports double the bandwidth of its predecessor, DDR4 with 4.8 gigabits per second possible -- but not shipping at launch.

DDR5 also supports on-die ECC scaling features, which enable manufacturing on advanced process nodes.

"The DDR5 standard offers the industry a critical advancement in main memory performance to enable the next-generation of computing required to turn data into insight across cloud, enterprise, networking, high-performance computing and artificial intelligence applications," said Frank Ross, JEDEC Board of Directors member and senior member of Technical Staff at Micron.

Power requirements were dropped from 1.2V to 1.1V compared to DDR4. A voltage regulator on DIMM design reduces power consumption and offers better voltage tolerance for better DRAM yields. DDR5 uses the MIPI Alliance I3C Basic specification for system management bus.

"DDR5 is prepared to improve the Computing Performance by applying various features to overcome future technology scaling challenge and improve performance compared to DDR4. On this basis, DDR5 will lead the evolution of the data-centric era, and will play a pivotal role in the 4th Industrial Revolution," said Uksong Kang, Head of DRAM Product Planning at SK hynix, one of the JEDEC members. "SK hynix is opening up a new sector in the market through the development of the industry's first DDR5 that meets JEDEC standards. We have been working with many partners to verify DDR5 Ecosystem through development of test chips, and modules since 2018, and doing our best to secure mass-production levels in the second half of this year."

The product is expected to arrive in data centers and other cloud computing applications first, and migrate to consumers shortly thereafter. JEDEC has made the spec available for purchase.

Comments

  • Reply 1 of 9
    XedXed Posts: 1,028member
    A bit off topic, but I'm looking forward to Si allowing us (the consumer) to have devices with faster RAM without waiting forever for Intel to adopt it.
    MacProwatto_cobra
  • Reply 2 of 9
    viclauyycviclauyyc Posts: 683member
    Xed said:
    A bit off topic, but I'm looking forward to Si allowing us (the consumer) to have devices with faster RAM without waiting forever for Intel to adopt it.
    Don’t think that will happen in portable Mac line. Apple is hooked on soldering on ram. 

    But it could happen in desktop Mac. 
  • Reply 3 of 9
    XedXed Posts: 1,028member
    viclauyyc said:
    Xed said:
    A bit off topic, but I'm looking forward to Si allowing us (the consumer) to have devices with faster RAM without waiting forever for Intel to adopt it.
    Don’t think that will happen in portable Mac line. Apple is hooked on soldering on ram. 

    But it could happen in desktop Mac. 
    You don't think LPDDR4 will be coming to Mac notebooks? I'd be surprised if the next Si Mac notebooks are still using LPDDR3 RAM.
    watto_cobra
  • Reply 4 of 9
    flywayflyway Posts: 1member
    GPUs such as the AMD Radeon Pro 5500M use GDDR6 and the 5600M uses HBM2 in the 16" MacBook Pro.
    Is DDR5 mainly for the CPU and how does it compare to GDDR6 and HBM2?
    edited July 2020 watto_cobra
  • Reply 5 of 9
    thttht Posts: 4,030member
    flyway said:
    GPUs such as the AMD Radeon Pro 5500M use GDDR6 and the 5600M uses HBM2 in the 16" MacBook Pro.
    Is DDR5 mainly for the CPU and how does it compare to GDDR6 and HBM2?
    It depends on how many channels of each memory.

    2 channels of DDR4: 50 GB/s
    2 channels of DDR5: 100 GB/s
    2 channels of GDDR6: 250 GB/s
    2 channels of HBM2: 1000 GB/s

    DDR5 is for system or main memory for PCs, servers and such, but it usually comes down to cost. If HBM was cheap, there would be systems using it for main memory, but it is two expensive to be used as system memory for a regular PC. It will be interesting if Apple uses it as main memory for high end Apple Silicon Macs though. I'm almost half expecting it.

    There are latency differences that can sway usage of one type of RAM over the other depending on primary application as well.
    GG1mattinozMacProapplguyrundhvidqwerty52watto_cobra
  • Reply 6 of 9
    DetnatorDetnator Posts: 179member
    tht said:
    flyway said:
    GPUs such as the AMD Radeon Pro 5500M use GDDR6 and the 5600M uses HBM2 in the 16" MacBook Pro.
    Is DDR5 mainly for the CPU and how does it compare to GDDR6 and HBM2?
    It depends on how many channels of each memory.

    2 channels of DDR4: 50 GB/s
    2 channels of DDR5: 100 GB/s
    2 channels of GDDR6: 250 GB/s
    2 channels of HBM2: 1000 GB/s

    DDR5 is for system or main memory for PCs, servers and such, but it usually comes down to cost. If HBM was cheap, there would be systems using it for main memory, but it is two expensive to be used as system memory for a regular PC. It will be interesting if Apple uses it as main memory for high end Apple Silicon Macs though. I'm almost half expecting it.

    There are latency differences that can sway usage of one type of RAM over the other depending on primary application as well.
    Just looking at that last stat — 1 Terabyte per second. That’s just... wow.  Imagine a Mac Pro with 1.5 TB of that and a TB of it as a RAM disk. Lol. Of course not practical.** But yeah... 

    In my native tongue: Crikey!


    **I miss the days when a RAM disk could perpetuate over a restart.  I think the beige G3’s (before the blue and white ones) were the last ones that could do that.  With enough of it you could install an OS on it and boot from it. That was cool. Imagine a 1TB/second boot RAM disk. Lol. 



    edited July 2020 watto_cobra
  • Reply 7 of 9
    Detnator said:
    **I miss the days when a RAM disk could perpetuate over a restart.  I think the beige G3’s (before the blue and white ones) were the last ones that could do that.  With enough of it you could install an OS on it and boot from it. That was cool. Imagine a 1TB/second boot RAM disk. Lol.
    Dont forget these flavour!  ;) mix of "SSD and DRAM" tech intel persistent memory https://www.intel.com/content/www/us/en/architecture-and-technology/optane-dc-persistent-memory.html  :)
    edited July 2020 watto_cobra
  • Reply 8 of 9
    thttht Posts: 4,030member
    Detnator said:
    tht said:
    flyway said:
    GPUs such as the AMD Radeon Pro 5500M use GDDR6 and the 5600M uses HBM2 in the 16" MacBook Pro.
    Is DDR5 mainly for the CPU and how does it compare to GDDR6 and HBM2?
    It depends on how many channels of each memory.

    2 channels of DDR4: 50 GB/s
    2 channels of DDR5: 100 GB/s
    2 channels of GDDR6: 250 GB/s
    2 channels of HBM2: 1000 GB/s

    DDR5 is for system or main memory for PCs, servers and such, but it usually comes down to cost. If HBM was cheap, there would be systems using it for main memory, but it is two expensive to be used as system memory for a regular PC. It will be interesting if Apple uses it as main memory for high end Apple Silicon Macs though. I'm almost half expecting it.

    There are latency differences that can sway usage of one type of RAM over the other depending on primary application as well.
    Just looking at that last stat — 1 Terabyte per second. That’s just... wow.  Imagine a Mac Pro with 1.5 TB of that and a TB of it as a RAM disk. Lol. Of course not practical.** But yeah... 

    In my native tongue: Crikey!

    **I miss the days when a RAM disk could perpetuate over a restart.  I think the beige G3’s (before the blue and white ones) were the last ones that could do that.  With enough of it you could install an OS on it and boot from it. That was cool. Imagine a 1TB/second boot RAM disk. Lol. 
    Realistically, The most Apple could implement with HBM2E is about 128 GB of HBM per socket. It would be like a $10,000 upgrade. And, 128 GB is kind of doubtful even. 8 channels of HBM2E would be something like 4 TB/s bandwidth, but only the well monied can afford it.

    They sell the Radeon Pro Vega 2 w/32 GB of HBM for $2400. Just multiple by 4, and then add some more. Or look at the 2 Radeon Pro Vega II Duo MPX module upgrade price. Total of 128 GB of HBM with 4 GPUs: $10,800.

    Apple is seemingly saying Apple Silicon Macs will have main memory in the SoC package. That has some big ramifications that people still need to digest. It's going to be some very interesting packaging if they put 128 GB of LPDDR5 in-package, let alone 128 GB of HBM. If they make 8 GB/s SSD standard with smaller pools of high speed system memory, workflows that require 1 TB of memory might work out fine or better.
    watto_cobra
  • Reply 9 of 9
    mpantonempantone Posts: 1,609member
    flyway said:
    GPUs such as the AMD Radeon Pro 5500M use GDDR6 and the 5600M uses HBM2 in the 16" MacBook Pro.
    Is DDR5 mainly for the CPU and how does it compare to GDDR6 and HBM2?
    They aren't interchangeable.

    DDR4 and DDR5 are specs for system memory on desktop computers.

    LPDDR is for notebook computers, LP standing for Low Power. This type of memory is typically more expensive than the standard desktop computing RAM. 

    The 'G' in GDDR is graphics memory for discrete GPUs. You cannot stick GDDR into a desktop computer's system memory slots. They are not compatible.

    HBM is a newer mobile graphics memory type. Rather than hang separately off the graphics bus, it is usually more highly integrated with the GPU itself, often in the same package. This technology can provide better mobile graphics performance but with higher cost.
    edited July 2020 fastasleepwatto_cobra
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