Double Height DDR4: 32GB Modules from G.Skill and ZADAK Reviewed
by Ian Cutress & Gavin Bonshor on January 23, 2019 9:00 AM ESTPower Analysis
One of the interesting aspects of the double height memory is how it affects power consumption. It would be natural to assume that double the number of chips and EPROMs would result in double the power draw of a standard capacity module, and the power per GB should be similar.
To measure the power consumption, we ran Intel's Power Gadget 3.5.0 utility during benchmark runs in our POV-Ray 3.7.1 test and in our Memory Latency Checker. POV-Ray 3.7 is a rendering based benchmark which stresses a system - It's a good indicator of memory stability and overall performance so it made it a natural choice for a power point of view. Our second test involves our MLC2 memory benchmark which is purely memory focused and loads the memory with high workloads as well as testing latency.
POV-Ray 3.7: link
The Persistence of Vision Ray Tracer, or POV-Ray, is a freeware package for as the name suggests, ray tracing. It is a pure renderer, rather than modeling software, but the latest beta version contains a handy benchmark for stressing all processing threads on a platform. We have been using this test in motherboard reviews to test memory stability at various CPU speeds to good effect – if it passes the test, the IMC in the CPU is stable for a given CPU speed. As a CPU test, it runs for approximately 1-2 minutes on high-end platforms.
On average when directly comparing the G.Skill TridentZ and TridentZ DC RAM, the power consumption on average in POV-Ray was 285% higher. This is a noticeable jump over two sticks and more than double in terms of overall power used. If we convert this down to average energy per gigabyte:
There is still an additional penalty in energy for using the new modules per GB.
Memory Latency Checker: link
Intel's Memory Latency checker is a tool designed to measure memory latency and bandwidth. MLC measures multiple aspects of DRAM with idle and load latencies, cache to cache data transfer latencies and peak memory bandwidth. The benchmark focuses purely on the memory and is influenced by higher clock speeds and latency timings.
Over a longer duration and in a high memory weighted benchmark such as MLC2, the power variation from the double capacity to the standard was more consistent with what was initially expected; double the power consumption for double capacity RAM. For what it's worth, the Corsair Vengeance LPX kit at 1.2 V was no better off from a power consumption standpoint than the 1.35 V kits tested.
If we compare energy per gigabyte, it is actually very competitive compared to the smaller kits. Here, the 2x8GB kit is actually consuming the most energy per GB, which suggests that the static power is a significant proportion of this analysis.
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prateekprakash - Thursday, January 24, 2019 - link
Could you please mention the names of the motherboards which did not post with these memories?Also could you please try these with Intel 6xxx/ 7xxx series CPUs with 2xx chipsets ( z270, b250).
mito0815 - Thursday, January 24, 2019 - link
Any thoughts on how scalable this apporach is? I mean...the obvious issues (heatsink fan clearance being one of them) aside, 4-row-high-DIMMs would look absolutely hilarious. I'd buy them. Just for the joke.KarlKastor - Thursday, January 24, 2019 - link
I don't get why there is a need for double height.There are lots of DIMMs in the market, that have 18 ICs per side on a regular DIMM.
I think it's just marketing, to show visually they have something new. The Cooler occupies the space anyway. But don't get, why every Tech-website mention it's neccessary.
Targon - Thursday, January 24, 2019 - link
I suspect it is all about the memory density. So, rather than trying to get 7nm fab process RAM, these companies are using less expensive chips and just increasing the size of the board to compensate, plus the need to connect the RAM chips on the DIMM. What sort of timings are on these things, 2T, 3T, or 4T for the command rate? How about the latency ratings?KarlKastor - Friday, January 25, 2019 - link
Mh? I talk not about the number of DRAM Dies. I speak just about the size of the PCB. What has lithographie to do with PCB size?Here u have 16 packages per side. There are a lot of normal sized DIMMs outside with that amount of packages.
Danvelopment - Friday, January 25, 2019 - link
What are the use cases? I would have thought that, by the time you need those sort of capacities, you would be better served by a quad channel Xeon.NoSoMo - Friday, January 25, 2019 - link
Interesting -- now if they could just pair them with some 3D nand and allow hybrid RAM / storage like intel wants to do with optane. Perhaps it'd come in a variant that sees 16GB PC 3000 and a slot similar to M.2 with capacities that mirror that of NVMEs thus moving storage over to the RAM bus and freeing up the PCI bus. The modules would be L shaped so that the storage addition completes the form factor thus allowing it to retain the same profile as these taller units, vs having a module hanging off the side.13Gigatons - Wednesday, January 30, 2019 - link
Maybe they could focus on lowering the price????Other then that what is the case use?
DPete27 - Tuesday, February 12, 2019 - link
You can fit 2 SODIMMs using a single locking mechanism on each end within the limits of a mITX board. Surely that would be much easier and more universal.[img]https://lh3.googleusercontent.com/-L0fCpsbFSWA/We5...[/img]
ExclamationMediaLLC - Wednesday, July 10, 2019 - link
Hi Ian and Gavin! Very helpful article! I’m building a SFF workstation using these modules. I want to remove the heat spreaders but I’m afraid of damaging the DIMMs. I see you guys managed it. How risky is it? Is there anything special I should know about removing the RGB lighting strips? (Yes, everyone, I know it will void the warranty)