Cadence and Micron test Prototype 7nm DDR5 DRAM at 4400 MT/s
The DDR5 standard has not been finalized by JEDEC, but that is expected sometime this summer. Cadence created a test chip containing next-generation memory interface IP based on the discussions of what is likely to be in DDR5, and Micron produced the prototype DRAM chips.
The test chip was fabricated in TSMC's 7nm process, and contains both the controller and PHY. The two chips work together successfully achieving 4400 megatransfers per second, 37.5% faster than the fastest commercially available DDR4 memory. As far as we can tell, this is the first demonstration of DDR5 IP working with memory chips, as reportted on the Cadence blog.
DDR5 is mostly a capacity solution, more than performance. As die get bigger, they get slower, due to all sorts of laws of physics. As you start building a 16Gb die in 1X memory technology, the distances start to get really long, which changes a lot of core timing parameters for the worse. Then the memory can't keep up with the CPU and so has to be overdesigned, making it bigger still, and so on. But everyone wants more memory in each server, for bigger datasets, bigger databases, bigger netlists, and so on. Cloud companies charge people for the memory in their instances and so there is a direct line from memory capacity to revenue. The DDR5 standard is aimed at making 16Gb die easier and to make vertical stacking easier. The speed of the core is unchanged, but the I/O is higher speed.
DDR4 today is not up to its maximum speed. Mainstream parts today are 2400 megatransfers per second. The high end is 2667 (for example, look at what you get if you buy a Dell server). That will become mainstream this year, so we are still a couple of years from DDR4 reaching its maximum of 3200 megatransfers per second. DDR5 is expected to be 4400 megatransfers per second at first, which is what the Cadence test chip achieved. 6400 is the maximum but it will be many years before anyone gets there. As Marc kept emphasizing, DDR5 is more about capacity than performance. Memories "don't get faster very fast."
DDR5 Summary (not final)
- supply voltage will drop from 1.2V for DDR4 to 1.1V for DDR5
- data rates will run up to 6.4 Gbps eventually, 4.4Gbps initially
- on-die termination (pulled-up VDDQ) will be available for address buses, not just data buses
What's Next?
Cadence plans to be first again with IP for LPDDR5 and future generations of other memory standards such as HBM. I'm sure I'll be covering them when we are ready to announce.
Senior Member
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Joined: 2008-10-13
Wow, this would be a huge jump if these are meant to start at 4.4ghz, remember when ddr4 first came out it only went to 2133mhz at first, so wasnt a huge increase over ddr3
Can already see G.skills and corsair trying to push these to 7000mhz XD
And DDR3 was 800/1066/1333 at first as well. Now we have DDR3 2133+. So I was 100% not surprised DDR4 launched at 2133.
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Posts: 59
Joined: 2016-08-12
you cant teach an old dog new tricks, usless ddr memory again and again .. selling this old tech forever - again. what about the timings ? 30 ?40 ? even my old ddr1 had better latency then this junk. how about hbm for system ram ?
Senior Member
Posts: 442
Joined: 2013-04-05
The biggest problems with extremely tight timings is the memory controller in the CPU, though.
The motherboard also factors in quite a bit. I watched a vid where DDR4 4000 CL 12 was attainable. The reason given was the single memory bank per channel.
If DDR5 can 4X the memory on a stick it would be possible to create enthusiast boards with only 2 memory banks to leverage this latency improving technique while still allowing for huge memory capacity.
Senior Member
Posts: 558
Joined: 2006-05-22
Wait a sec, they also working this out as the fastest available DDR 4 is 3200 which is bullsh!t. That is where they get an increase of 37.5%. But I can buy DDR 4 Gskill F4-4266, which will make DDR5 only 3% faster, I have seen reviews of DDR 4 4600 maybe even higher.
That is why I say DDR5 standard speed should be 6400.
I am guessing DDR5 will prob go all the way up to 9000 - 10000mhz
Senior Member
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Joined: 2006-05-22
Standard speeds should be.
DDR 1 : 400
DDR 2 : 800
DDR 3 : 1600
DDR 4 : 3200
DDR 5 : 6400