Tuesday, September 25th 2012

JEDEC Announces Publication of DDR4 Standard

JEDEC Solid State Technology Association, the global leader in the development of standards for the microelectronics industry, today announced the initial publication of its widely-anticipated Synchronous DDR4 (Double Data Rate 4) standard. JEDEC DDR4 (JESD79-4) has been defined to provide higher performance, with improved reliability and reduced power, thereby representing a significant achievement relative to previous DRAM memory technologies. The new DDR4 standard is available for free download from the JEDEC website at http://www.jedec.org/standards-documents/results/jesd79-4%20ddr4.

DDR4 offers a range of innovative features designed to enable high speed operation and broad applicability in a variety of applications including servers, laptops, desktop PCs and consumer products. In addition to the advantages described later in this release, the new technology has been defined with a goal of simplifying migration and enabling adoption of an industry-wide standard.

To facilitate comprehension and early adoption of the DDR4 standard, JEDEC is hosting a two-day DDR4 Technical Workshop in Santa Clara, CA on October 30 and 31. For online registration and agenda information visit: http://www.jedec.org/ddr4workshop.

The per-pin data rate for DDR4 is specified as 1.6 giga transfers per second to an initial maximum objective of 3.2 giga transfers per second. With DDR3 exceeding its original targeted performance of 1.6 GT/s, it is likely that higher performance speed grades will be added in a future DDR4 update. Other DDR4 attributes tightly intertwined with the planned speed grades, enabling device functionality as well as application adoption, include: a pseudo open drain interface on the DQ bus, a geardown mode for 2,667 MT/s per DQ and beyond, bank group architecture, internally generated VrefDQ and improved training modes.

The DDR4 architecture is an 8n prefetch with two or four selectable bank groups. This design will permit the DDR4 memory devices to have separate activation, read, write or refresh operations underway in each unique bank group. This concept will also improve overall memory efficiency and bandwidth, especially when small memory granularities are used. More information about additional features may be found on the JEDEC website.

In addition, DDR4 has been designed in such a way that stacked memory devices may prove to be a key factor during the lifetime of the technology, with stacks of up to 8 memory devices presenting only a single signal load.

Joe Macri, Chairman of JEDEC's JC-42.3 Subcommittee for DRAM Memories, said: "The publication of the JEDEC DDR4 standard represents the culmination of years of dedicated effort by memory device, system, component and module producers worldwide. The new standard will enable next generation systems to achieve greater performance, significantly increased packaging density and improved reliability - with lower power consumption."

"The industry has been looking forward to the publication of this standard for some time," noted Desi Rhoden, Chairman JC-42 Memory Committee and Executive VP Montage Technology. "The current publication will provide early adopters with the critical information required to utilize the emerging DDR4 devices. Subsequent publications are planned to address material not yet finalized in time for this publication. As with all JEDEC standardization activities, industry participation is highly valued - companies interested in participating in JEDEC may visit the JEDEC website at www.jedec.org or call 703-907-7560 for more information."

Industry Support for DDR4
"Following finalization of JEDEC DDR4 specifications, Samsung continues to provide highly advanced-performance, low-power DRAM solutions in furthering the development of state-of-the-art next-generation green IT systems," said Byungse So, Senior Vice President, Memory Product Planning and Application Engineering, Device Solutions, Samsung Electronics. "Together with our global customers, we will continue to develop economic IT systems with high energy-efficiency to enlarge the premium memory market in support of the most advanced computing modules and solutions."

"The publication of the DDR4 standard is a great milestone leading up to the launch of this next generation of DRAM," said Robert Feurle, vice president for Micron's DRAM marketing. "Improvements in performance and power consumption make DDR4 an attractive memory solution for the next generation of enterprise and consumer products, and we look forward to driving this technology into the marketplace."
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17 Comments on JEDEC Announces Publication of DDR4 Standard

Quicker memory is always a good thing. Uh, DDR4 with GPU + CPU unified memory space which requires more bandwidth is good. Latency of course will remain the same, or will get a bit higher on first modules as always.

That stacking possibility promises good densities and the lower voltage will get our laptops more time on battery.
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Just seemed like a bunch of marketing talk with a few numbers to me. How big of a step will ddr4 make?
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About damn time, can't wait to get rich and build me a computer that can use it.
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Basic features of DDR4:
- starting at DDR-1600, spec upto DDR-3200, extensions are likely (vs. DDR-800 to DDR-1600 and extended to DDR-1866 and finally DDR-2133)
- 1.2V operating voltage (vs. 1.5V for DDR3)
- multiple dies in a package for higher capacities.
- one DIMM per channel

That last thing will have a great impact for users. DDR4 is point-to-point in nature, meaning only one DIMM per channel is allowed. And that means most DDR4 motherboards will likely have only two DIMM slots as CPU memory controller bus widths and motherboard tracings would have to be increased beyond conventional 128bits (192bits for Nehalem). And that's not likely to happen as it would seriously drive PCB complexity (=cost) up.
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Initialised, post: 2730650"
Dammit, just upgraded to DDR3
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Initialised, post: 2730650"
Dammit, just upgraded to DDR3
My PC still has DDR2, but this is good news.
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Isenstaedt, post: 2730830"
My PC still has DDR2, but this is good news.
I also run DDR2@1066Mhz...:)
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I know it always starts this way, with a low initial spec, but it would be pretty rad if by the time we had 20nm CPUs (no, not gpus) from AMD/nvidia we had chips specced the same as lower-end gddr5. If the GPU is going to more-or-less be allocated half the bandwidth of a CPU from now on it really needs to happen, and realistically I don't see why it couldn't. Also, ddr4 could then realistically replace (g)ddr3/5 as good-enough on newer low-end discrete gpus.

Granted, while AMD embraces 1866 ddr3 and they seemed to have gone even further with encouraging memory overclocking (or rather memory profiles) with Trinity, that's because they really HAD to. While that's lovely, standards are better.

I'm not worried about Intel/nvidia, they'll finagle some cache/buffer with a smaller gpu in their cpus and be just fine. If AMD continues to shoot for the moon (ie we end up with a cpu that has similar floating point as current-to-upcoming x700 28nm gpus) without doing something similar the spec really needs to ramp, and fast.
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the complexity of MB will be not get high, because the memory controller this days are located in the cpu. So in the future maybe we will have a cpu (ore more) with a memory controller with 2 or more channels. that in ideea that one channel will take 64bits
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Ferrum Master
Ok, the thread goes like that, who owns stil la Fast Page or EDO ram? :D

I have still lying in the attic a 8088 machine with socketable RAM IC's - man 64KB :D :D (I use it as dummy load for PSU to light up my halogen 12V bulbs there, quite interesting, the thing still boot ups, judging from sounds... :p
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If no workaround is found for the one-dimm-per-channel thing, most of us will be better off sticking to DDR3. I can't see there being any significant performance difference between DDR3-1866 and DDR4-2400, or whatever the initial standard is. Just like there isn't any signifcant performance difference between dual and quad channel today. Especially if latencies are very poor to start with.
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adrianx, post: 2731145"
the complexity of MB will be not get high, because the memory controller this days are located in the cpu.
Feel free to explain why the whereabouts of the mem ctrl would make a difference?
It's the massive memory tracing requirements that cause the complexity when going higher than 128bit.
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largon, post: 2731433"
Feel free to explain why the whereabouts of the mem ctrl would make a difference?
It's the massive memory tracing requirements that cause the complexity when going higher than 128bit.
Tracing will increase. We may only see the additional slots on highend platforms in the first genration of mobo's using DDR4 but it will happen.
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The standard will be 8GB sticks ie 16GB total, or for faster or lower end mem 4GB ie 8GB. That is plenty
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CPU support

I don't think Intel Haswell will have support for DDR4, but probably Haswell-EX will have.
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