Kaby Lake Core i7-7500U Versus Skylake Core i7-6500U on Dell XPS 13

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HEVC/H.265 Video Decode Performance

One of the big new features of Kaby Lake is that there is now HEVC hardware encode/decode block in chip. This frees up the CPU and GPU workload and puts it on the new dedicated hardware that was designed to run it from the start. To test this new feature, we played Tears of Steel (4K, 24 FPS, 20mbps 10-bit HEVC (H.265) video file in full screen mode using the default Windows Movies & TV app that comes in Windows 10 Anniversary Edition. While this was playing we recorded what the CPU and GPU was doing during video playback and got some very interesting results.

HEVC hardware encode/decode performance

Here is a look at an 8 minute section of the overall CPU utilization that was being observed while the video was being played back. On the new Intel Core i7-7500U processor we averaged right around 11% CPU utilization and noted that the video was played back pretty smoothly. On last years Intel Core i7-6500U processor the CPU utilization averaged up around 44% and we noticed several placed where the video playback was not smooth.

HEVC hardware encode/decode performance

We also noticed that the GPU clock speed was much higher on the Intel Core i7-6500U than the Intel Core i7-7500U!

The take home message here is that if HEVC/H.265 video encode/decode performance is a point of concern for you, then you’ll want to go with an Intel 7th Gen Kaby Lake processor for the additional decode block that was added this generation. This is a big deal for mobile users as the lower CPU utilization and GPU clock speeds means that you’ll have greatly improved battery life when watching videos. Kaby Lake also supports Google’s upcoming VP9 video coding format, so Intel 7th Gen Core processors are clearly the way to go for H.265 and VP9 video codecs.

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  • Alfred Zanini

    I have an option for an i7 6500u model for 940$ us. Worth it?


    Not sure if I’m just seeing it wrong, but would these scores not be the same if core “clock speeds” were the same…!? I get that there is more performance to be had on the kaby, but this would not be enough for me to jump ship for such a small incremental performance increase.

  • Spineman

    Great review. Thanks. Intel should have just waited on this one. Not enough to warrant an upgrade. They need to acquire Nvidia and get some real graphics pros on board. Yawn! It will hopefully lower the Surface Pro 4 pricing even more as rich boys upgrade to this “power” processor. lol.

    • AdamBoy64

      True, if you’re already using an i7-6500u there’s not much of a jump.

      It’s good for those in the market though to be able to compare. I was considering a 6500u as it didn’t seem much different, but it seems like there’s more of a jump than I expected.

  • Greg Zeng

    Running on battery makes the upgrade very worthwhile. These improvements should also be visible on other products with the new CPU.

  • Patrick DuChene

    Great article. Its not very often we see such thorough information. Thanks for that. Helps clarify a bit more of the true benefits on Kaby Lake over Skylake.
    Nice work

  • anon

    10% more performance for 10% higher clock speed? If scores are not normalized its difficult to compare when products are sooo similar.
    The performance boost could be alleged to a higher absolute performance, but its not.

    Also in the power comsumption chart, HEV (page 8) decoding power use seems missleading. You cannot use a line graph to compare different usages of power because the lines between the points mean a progression which is non existant. Should be a bar chart as well.

    I like very much legit, and I think you should pay attention to this kind of details.

    • anon

      The claim is the 14nm+ process achieves a higher clock with equivalent TDP.

    • Nathan Kirsch

      I get your point on the chart, so I updated it! Thanks for the feedback and we always strive to make the reviews as good as possible!

      • anon

        This kind of feedback is what makes legit what it is. Kudos for you.

  • Earl Keim

    Excellent article, Nathan. Nice to see one can have a long flight overseas, etc. and never run out of battery.