DDR4 Memory Scaling on Intel Z170 – Finding The Best DDR4 Memory Kit Speed

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Answering What DDR4 Clock Speed is Best

Shortly ahead of the Intel Z170 platform launch we heard that the memory controller Intel developed for Skylake was amazing and that the new Intel Core i7-6700K and Core i5-6600K could come close running DDR4 4000 MHz memory kits in dual-channel. Just days before Intel launched their two new K-Skus that are aimed at enthusiasts and gamers we noticed that G.Skill released a dozen new dual-channel DDR4 memory kits with speeds ranging from 2133 MHz to 4000 MHz. G.Skill is the first company to release retail memory kits at 4000MHz and it took the release of the latest 6th generation Intel Core processor and Z170 motherboards to make that happen!

G.Skill DDR4 Memory Kits For Intel Z170

The new G.SKill Ripjaws V 8GB (2x4GB) memory kits are already all available on Newegg and range in price between $62.99 and $399.99. The lowest priced kit is actually the DDR4-2400 kit at $62.99 and you can move up to a DDR4-2666 kit for only two dollars more. The price differences between kits is actually reasonable as you can go from a DDR4-2400 and DDR4-3200 kit for only $17 extra. If you wanted to go with a DDR4-3466 or DDR4-3600 kit you better open your wallet though as the price jumps up to $230 and $400, respectively.

  • G.Skill Ripjaws V 8GB (2x4GB) DDR4 2133MHz Kit – F4-2133C15D-8GVR – $64.99 Shipped
  • G.Skill Ripjaws V 8GB (2x4GB) DDR4 2400MHz Kit – F4-2400C15D-8GVR – $62.99 Shipped
  • G.Skill Ripjaws V 8GB (2x4GB) DDR4 2666MHz Kit – F4-2666C15D-8GVR – $64.99 Shipped
  • G.Skill Ripjaws V 8GB (2x4GB) DDR4 2800MHz Kit – F4-2800C15D-8GVR – $69.99 Shipped
  • G.Skill Ripjaws V 8GB (2x4GB) DDR4 3000MHz Kit – F4-3000C15D-8GVR – $72.99 Shipped
  • G.Skill Ripjaws V 8GB (2x4GB) DDR4 3200MHz Kit – F4-3200C16D-8GVK – $79.99 Shipped
  • G.Skill Ripjaws V 8GB (2x4GB) DDR4 3466MHz Kit – F4-3466C16D-8GVK – $229.99 Shipped
  • G.Skill Ripjaws V 8GB (2x4GB) DDR4 3600MHz Kit – F4-3600C17D-8GVK – $399.99 Shipped

The point of this article today is to look at all the above clock speeds and then overclock our kit even faster to see what the sweet spot is for DDR4 memory on the Intel Z170 platform. There will be many thousands of people building a new system and looking possibly their first DDR4 memory kit ever and we wanted to help them find the best DDR4 memory kit! To answer this question, we needed to look at DDR4 frequency on the LGA1151 platform to see how memory acts with Intel’s latest Skylake processor microarchitecture.

G.Skill Ripjaws V

Obviously, the memory controller used on Skylake is rumored to be good, so we asked G.Skill if we could get one of their news kits of memory in to investigate on our own.  G.Skill graciously sent over a RipJaws V 8GB (4GB x 2) 3600MHz DDR4 memory kit over for us to play around with that is sold under part number F3600C17D-8GVK.  G.Skill Ripjaws V DDR4 memory kits are available in Blazing Red, Steel Blue, Radiant Silver, Gunmetal Gray, and Classic Black color schemes.

G.Skill Ripjaws V DDR4 3600MHz 8GB Kit

This memory kit operates at DDR4-3600 with CL17 timings of 17-18-18-38 at 1.35V and is plug-and-play ready thanks to have an Intel XMP 2.0 profile.

G.Skill Ripjaws V and ASUS Z170 Deluxe

Most all Intel Z170 boards and 6th Gen Core ‘Skylake’ processors should be able to run DDR4 memory kits ranging in speed from 2133 MHz to 3200 MHz without issue, but getting beyond 3200 MHz might involve some tweaking. We picked the ASUS Z170 Deluxe motherboard for testing as it is one of the best boards for memory overclocking according to the memory manufactures. We were able to run the G.Skill F3600C17D-8GVK memory kit on this board at clock speeds of 2133 MHz and 3866 MHz with the memory running at its stock voltage of 1.35V. The fastest memory kit available in the Ripjaws V line is clocked at 3700MHz, so we were able to overclock this memory kit beyond any Ripjaws V kit that you can purchase today.

To get such high clock speeds we did have to go into the UEFI and tweak some things manually to get things stable as pushed the clock speeds up. We learned that the VCCIO/System Agent voltage are both important for memory clocking on the Z170 platform. We found that when running this particular dual-channel kit of memory at DDR4-3400 or higher that we needed to bump up the CPU VCCIO Voltage to 1.250V from 0.968V and the CPU System Agent Voltage to 1.300V from 1.056V.  Increasing the voltages higher than this doesn’t appear to help memory overclocking, so we don’t suggest trying higher than that. You can see the ASUS Z170 Deluxe UEFI 0603 menus above with the settings we had to change to overclock both the processor and DDR4 memory.


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  • David Keller

    Excellent review, thanks!!

  • emtee

    Sigh, more useless ‘memory’ benchmarks… you guys shouldnt even benchmark anything if you don’t know what you’re doing… memory bandwidth will only make a significant difference in CPU limited titles and/or scenarios, something simply never tested by anyone…

  • John Truckasaurus

    DDR4 2133MHz: dirty RAM peasants.
    Looks like I will be struck down by the tyrannical mainboard manufacturers and their ITX-caprices.

  • Ray Koopa

    So I recently bought the Ripjaws F4-3400C16D-16GVK, categorized as DDR4-3400, and the Asus Z170 Pro Gamer Edition, but if I look into the BIOS, it says it runs at 2133 MHz? I’m a bit new here… shouldn’t it say it runs at 3400 MHz? Or is the categorization unequal to real speed?

    • AtheO

      I think you need to enable XMP in the BIOS.

      • Ray Koopa

        I tried that, it asked me to use some optimized settings or Intel stock ones… I tried with both, but with both my PC didn’t boot up anymore and I had to reset back to the previous settings…

        • Jared Henderson

          Dude I have the same issue. Manually changed it to 2400mhz and still won’t boot. Xmp profile 1 doesn’t work either

        • Ray Koopa

          I couldn’t get my system to boot at all with XMP on. It always just turned on and black screened, not doing anything, and reset itself after 1 minute.

        • Kevlar

          I know these comments are really old but I had the same issue on my ASRock board. I had to set the XMP and then manually set the ram’s rated voltage. After rebooting it was running at the XMP speed. Also make sure your bios is up to date for the best compatibility.

        • Mikołaj Łajming

          My computer needed about 3-5 minutes to boot after setting on XMP and after every change in RAM frequency, voltage or so, but after that it booted up in no time as always

    • Robcabob1

      Visit support for motherboard and see if it has compatibility with that specific RAM. If not, you may not get full use. MSI has complete specifications for it.

      I personally bought the wrong RAM and could only OC up to one below mac (3200mhz RAM could only boot one choice under max ;30??mhz)

  • Dave4321


  • Justifiable187

    For Handbrake test, it has been my experience that the read from the source drive is the bottleneck. With that, I would really like to see someone create a ram drive, put the Big Buck Bunny source into it, and see those results.

  • Aron_1

    Do these results hold on a non-overclocked CPU on a Z170 board and is this still possible without a K series CPU? 🙂

  • THU31

    You should not test the average framerate, you should test the minimum framerate, because that is what is mostly affected by system memory speed. In CPU-bound scenarios you can often get 5-10 more FPS with faster memory, which is significant.
    You do not change your system memory too often, it might last you until the next memory standard comes (so probably way more than 5 years), which means investing in faster memory is not a bad idea.

    • Iluv2raceit

      You make a good point, but you forgot to mention that system memory will only become a factor with frame rates based upon the game’s coding as well as the resolution that you play the game.

      • Johan Krüger Haglert

        “only become a factor with frame rates based upon the game’s coding”

        lol what? And what do you mean isn’t included in that?

    • Ian Barlow

      “…you should test the minimum framerate…”

      Agreed. Plenty of others have done this and the benefits are always shown to be significant. No disrespect intended, but these tests tell us almost nothing about the benefits of faster RAM for fairly obvious reasons.

  • Faiakes

    Could the article be updated with figures using the just released HyperX Savage line?
    It seems to be 1 CL less than the G.Skill up to 2800.

    • legitreviews

      Re-do over 225 benchmarks for 1CL less? The performance might be a tad higher and the scaling should be about the same, so that’s days of work for basically the same results!

      • Faiakes

        Hey, a guy can hope! 🙂

        Thanks anyway

  • Faiakes


    I see your RAM runs at 1T.
    How is that even possible!
    Can you share how you managed it (BIOS settings, etc)?

    • legitreviews

      We manually set the timings and you can see where the command rate value is set in slide 5 in the last gallery on the first page of the article!

      • Faiakes

        Thanks for the prompt reply.

        So all it took was manually setting DRAM Command Rate to 1?
        Nothing else was needed to get the RAM running at 1T?

        • legitreviews

          Nope, just change the setting manually from 2T to 1T!

        • Faiakes

          Well…I thought there was more to that.

          Excellent. I will try it and get back to you.

  • DinamykPT

    The older Ripjaws 4 memories aren’t compatible with z170-based motherboards?

    • Nathan Kirsch

      The XMP and SPD profiles likely were not set for Z170 based boards, so you’ll need to manually adjust the settings on some kits.

  • Noshuru

    Would it be possible to repeat the GTA V test with these settings: http://www.eurogamer.net/articles/digitalfoundry-2015-intel-skylake-core-i7-6700k-review

    (All Ultra, no AA, 980 Ti or Titan X clocked as high as they go, advanced tab maxed out)
    I’m really quizzed over these results. My current working assumption is that Skylake performs so well because even the lowest clocked DDR4 RAM available is 2133MHz. One of the settings in the advanced tab, namely Extended Distance Scaling, is hugely CPU dependent. With that setting off I get a whopping 40FPS more.
    Personally, I have a 2500K running at 4.8GHz, DDR3 RAM at 1600MHz. I get 64.8FPS with that setup.
    Hope to hear from you!

  • ramonzarat

    Love those scaling article! I would like to see i7-920 to 6700K @ 4GhZ scaling!

    • legitreviews

      Thanks, next time I’ll be sure to give 7-zip a shot!

  • musef1

    Interesting article.

    Just one thing, I noticed that in your chart on the final page, it says lower = better. Surely it should be higher = better?

    • Nathan Kirsch

      Good catch and a new chart has been inserted!

      • Ryan Snaca AniloHectycle

        Without a stock memory controller to a typically achievable overclocked comparison this is a very silly benchmarking/conclusion to be sure.

        • David Keller

          I’ve done a lot of benchmarking myself with my older 4790K with uncore between x44 and x48 and the only really benefits I ever saw were faster cache speeds and some latencies, up to a point. At one point cache speeds actually started to suffer. Which, as with most hardware, there is a sweet spot that is most efficient. OCing the uncore hasn’t produced any real world benefits that I’ve noticed. Although, that is one configuration and it’s DDR3. Can’t claim it’s universal. I have seen improved performance in Crysis 3 with faster memory speeds. One example that sadly, is pretty uncommon.

  • Anton

    Did you measure the power usage for the different frequencies? As the performance is quite similar throughout the test the temperature and power would be an interesting consideration when choosing the modules.

    • Nathan Kirsch

      From DDR4 2133 to 3733 we used 1.35V across the board, so it would likely be another flat line on a chart to look at. Temperatures would have been interesting to look at, but it’s a non-issue at these speeds as long as you have airflow in your case since we were only running 1.35V.

  • Shadowdane

    Wish you would of tested SLI configurations with the various memory kits. I’ve found on Haswell at least faster memory kits have a rather big impact with Multi-GPU configurations. For example I tested GTA5 on my system. Going from DDR3-1600 to DDR3-2400 saw a 8% performance improvement.

    • Nathan Kirsch

      I’ll toss in another GeForce GTX 980 Ti into the system and see if I spot a big jump up like that!

  • Selena Gomez

    Need better benchmarks for games. Higher speed RAM generally shows some (small) gains in situations that are CPU bound/bottlenecked.

    • MewkaKazami

      I’m pretty damn sure if you’re buying Skylake thats not gonna be a problem considering only i5-6600k and i7-6700k are out

      • Selena Gomez

        Go look up benchmarks, Skylake isn’t some huge advancement, it’s only slightly faster than Haswell so there’s obviously still going to be games that are more CPU bound than GPU.

        • MewkaKazami

          It’s actually not about performance but stability. Check Eurogamers review and you’ll see a lot of games get a huge improvement in minimum FPS over the old CPUs

        • shadowhedgehogz

          Look further down the page to the OC gfx card results, pretty much the same perf on both Haswell and Skylake. x99 is the better buy.. Also that small improvement is nowhere near “huge” as you say, a high end GPU upgrade would make a much much bigger difference.

        • Dan Eagen

          If you don’t plan on overclocking (99% of the population won’t) then Skylake presents massive improvements.

        • Mirko Opacic

          Like always when he throw out new cpu…few % better and more expensive then previous.

          Fucking Intel pussy…go amd kill them all

    • Nathan Kirsch

      Have any suggestions as to what better benchmarks would be for game titles? I always want to test using the best benchmarks possible.

      • Selena Gomez

        I’d like to see Arma 3. There are lots of other games although most only become CPU bound when you’re already at very high frame rates so the performance differences won’t be noticeable in the real world. Arma 3 on the other hand (all I can think of right now) is heavily bottlenecked, even a Skylake @ 5 Ghz probably wouldn’t be able to get 60 fps consistently in populated servers.

        Just make sure that whatever you test, since you’re not focusing on the GPU performance, ensure that the GPU is never near 100% load and that the bottleneck is clearly the CPU.

        • Nathan Kirsch

          For memory testing I hate using FRAPS as often you are seeing just tenths of a FPS difference between clock speeds or timings. The human element adds the PEBKAC issue, so I prefer to use built-in benchmarks for testing like this. I see some tools are out there for ARMA 3, but the results are scores and not FPS from the looks of it – https://forums.bistudio.com/topic/142875-arma3mark-benchmark-your-arma-3/

          Do you know of a tool for ARMA 3 that gives results in FPS?

        • lol

          There is a benchmark existing which shows its results in FPS (instead of a score): https://forums.bistudio.com/topic/177406-yet-another-arma-benchmark/ would be great to see Arma 3 included in your benchmarks in the future 🙂

          I am using a souble-sided (IC’s) G.Skill F3-2400C9D-8GTXD Kit (@ 2600 Mhz CL10-12-11-31 1T) + SSD in my 4,5 Ghz Haswell System because Arma requires that much bandwidth…

        • lol


      • JeffreyQC


        It’s possible to run the X264 HD benchmark? This Skylake dual channel DDR4 come close to the Quad Channel Intel Core i7-5960X. Skylake is faster for write speed, not bad!
        (For a cheaper CPU)

  • anon

    Very interesting article indeed.
    I would like to point out two things,
    In freq-timing vs. anything charts it would be interesting to use the y-scale as per unit and add at each measured point the actual value. This is very helpfull to keep a proportional scale and give perspective of the real performance impact.
    Also it would be interesting to see, in the first part of the article, a brief comparison of similar memories used in other platforms.
    These to points are meant to add perspective to the article.