Memory Frequency Scaling on Intel's Skull Canyon NUC - An Investigation
by Ganesh T S on August 29, 2016 8:00 AM ESTMiscellaneous Aspects and Concluding Remarks
Improved memory bandwidth and reduced latency constitute the performance benefits of using high frequency SODIMM kits in the NUC6i7KYK. Another aspect is the difference in power consumption between the various modules. Intel's Skylake-H datasheet mentions that increasing the DDR4 rate from 1866 MHz to 2133 MHz may lead to a TDP power penalty of up to 400mW. This is only on the processor side, and doesn't consider the memory kit at all. To get a full view of the impact of different memory kits, we monitored the power consumed at the wall by the Skull Canyon NUC with an idle desktop and averaged it over a duration of 1 hour.
As expected, higher frequency kits do consume more power, but, again, the differences are minimal and may even vary from one idle time interval to another.
We looked up the pricing for the various 32GB kits prior to posting, and found that the street price varied from $140 to $190. Thanks to its stellar specifications, the G.Skill Ripjaws F4-3000C16D-32GRS is able to command the highest street price. The Crucial kit is the most economical of the lot.
| Premium DRAM Options for the Skull Canyon NUC (NUC6i7KYK) | |||
| Memory Kit | Tested Frequency (MHz) |
Tested Timing (tCL-tRCD-tRP-tRAS-tRFC) |
Price (USD) |
| Corsair Vengeance CMSX32GX4M2A2666C18 |
2667 | 18-19-19-39-467 | $160 |
| Crucial Ballistix Sport LT BLS2K16G4S240FSD |
2400 | 16-16-16-39-421 | $140 |
| G.Skill Ripjaws F4-3000C16D-32GRS |
3067 | 16-18-18-43-421 | $190 |
| Kingston HyperX Impact HX424S14IBK2/32 |
2400 | 14-14-14-35-421 | $158 |
| Patriot Viper Series PV432G280C8SK |
2800 | 18-18-18-43-491 | $180 |
Wrapping things up, we have put various 32GB DDR4 SODIMM kits through different benchmarks in the NUC6i7KYK, and what we have found is that they all largely perform the same when it comes to real-world workloads. Strict speaking, faster kits do improve average performance, but the ever so slight performance increase isn't enough to matter. With that said, there are a few workloads that can definitely benefit from the faster memory kits, but they tend to be professional use-cases rather than the kinds of consumer workloads Skull Canyon was meant for, such as entry level gaming.
I suspect that the processor configuration (128MB eDRAM) is playing a major role in ensuring that the experience with normal real-world workloads remains the same irrespective of whether it is running a 2400 MHz C16 kit or a 3000 MHz C16 one. The eDRAM keeps the obvious memory bottleneck - the iGPU - from being bandwidth starved, and it can also better feed desktop applications in some situations as well. However if that's the case, then desktop and notebook system users with a different non-eDRAM processor might observe different results. Ultimately if price is not a major concern, going with the G.Skill Ripjaws 3000 MHz kit is good for any system that supports DDR4 SODIMMs operating at that frequency. Otherwise, we recommend that consumers go for the kit that offers the best value for money at the time of purchase.
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zodiacfml - Monday, August 29, 2016 - link
AMD APUs please.tipoo - Monday, August 29, 2016 - link
Neat test. Interesting that the Iris Pro barely sees any scaling with memory bandwidth, indicating to me that the eDRAM really does cover its bandwidth needs nicely.I feel like the SC NUC could have been more with another inch of cooling height though. The GPU drops back to its base clocks quickly, having so many more EUs than the Iris Pro 5200 should have brought more gains than we saw since it's not bandwidth bound.
mcmillanit - Monday, August 29, 2016 - link
I have a SC.I attached an nvidia gtx 750ti using the bplus v4.1 egpu adapter.
When version 2 of the thunderbolt adapters become available, I will probably switch to one of those, but for now, m.2 to pcie adapter is ugly, but works, and works well. It is only using pcie1 x4, but that is sufficient.
The user experience is vastly improved. The video is smooth, and without the thermal load of the GPU on the processor, the cpu stays much cooler while it maintains higher clock speeds when I game or watch youtube.
-Michael
powerarmour - Monday, August 29, 2016 - link
How about investigating where all the GPU reviews have gone?Ranger1065 - Tuesday, August 30, 2016 - link
Anandtech is so BROKEN....Ian Cutress - Tuesday, August 30, 2016 - link
We've hit every major CPU launch on day one with every CPU available at launch being tested for the last two years - over and above any other website coverage. So wait, broken?JackNSally - Wednesday, August 31, 2016 - link
CPU=/=GPUzaza - Monday, August 29, 2016 - link
intersting results. can you redo the test but using normal CPU socket. The eDRAM might have played a role keeping the bandwidth and latency in check, but to be sure we have to test the effect on normal socket. and is it possible to test also with DDR3? since some skylake motherboards do support DDR3 memeoryIan Cutress - Monday, August 29, 2016 - link
You mean what we posted last august? DDR4 vs DDR3L ?http://www.anandtech.com/show/9483/intel-skylake-r...
ganeshts - Monday, August 29, 2016 - link
(1) Skull Canyon uses BGA, so it is not possible to move to a non-eDRAM processor on this testbed.(2) As I have explained in the article, the only platform we could source that supports memory OC AND supports SODIMMs was the Skull Canyon NUC. Our focus was on the large number of OC-ed DDR4 SODIMMs that have come to the market in the last few months.
(3) Practical comparisons of DDR3 vs. DDR4 with real-life workloads is quite difficult because, in a real system, the boards would be completely different in terms of system configuration and there are too many factors involved that it wouldn't be possible to do an apples-to-apples comparison.