Core i7-5820K vs Core i7-8700K - 2D Performance

Published by Luca Rocchi on 10.03.19

There is a variety of customer groups in need of as much processing power as possible. Especially in the field of content creation, which includes editing pictures and videos or even rendering a complex scenery with beautiful effects, performance improvements quickly translate into higher income by the end of the month. With this series of articles we're going to compare two processors. The CPUs tested are being run at stock clocks as well as 4.2GHz and apart from that we will also vary the memory frequency. It is our goal to show which CPU is how much faster or slower than another one.


  • ASUS Rampage V Extreme
  • MSI Z370 Gaming Pro Carbon AC
  • Core i7-5820K @ Default
  • Core i7-5820K @ 4.2 GHz
  • Core i7-5820K @ 4.2 GHz DDR4-3000

  • Core i7-8700K @ Default
  • Core i7-8700K @ 4.2 GHz
  • Core i7-8700K @ 4.2 GHz DDR4-3000
Cooler Corsair Hydro H150i Pro RGB
Memory Corsair Vengeance LPX 4x4 16GB DDR4-2133 C15
Graphic card ASUS GeForce GTX 980
Hard disk
  • Intel 335 Series SSD 120 GB
  • Corsair Neutron NX500 NVMe PCIe SSD 400 GB
Power supply Seasonic X-1250
OS Windows 10 x64 Updated




First of all we’re going to have a closer look at performance differences with standard clock speeds. From our overall performance rating we see that the Core i7-8700K is on average 23% quicker than the Core i7-5820K. If we start searching for the benchmarks with best possible scaling on the i7-8700K, then we find that Handbrake H.265 runs 40% faster on this CPU and Photoshop benefits by 49%. We also had a closer look at power consumption and it's rather similar on both setups at default clocks.

4.2 GHz

When we set 4.2GHz on both processors we see that the Core i7-8700K is still 7% faster on average. While at stock clocks there wasn't a big difference in terms of power consumptions, we can't tell the same with 4.2GHz. This time we see a pretty big gap between the two CPUs. In full load, the Core i7-8700K requires 63 Watts less than the Core i7-5820K. The gap is everything but small.

4.2 GHz DDR4-3000

Having arrived at this point we’re not going to go through every single benchmark anymore since the overall results are still very similar. What’s much more interesting now is checking what performance differences there are when running DDR4 memory at 3000MHz with both processors, while the stock clocks are DDR4-2133. Overclocking the system with the Core i7-8700K inside we notice that the performance goes up by less than 1%. In the case of the Core i7-5820K the difference is around 3% on average. Overall there isn't a linear improvement due to the difference between the two CPUs. As you might know, the Core i7-8700K doesn't sport quad-channel feature like the Core i7-5820K.


A quick look at the performance differences between these two CPUs shows, that the Core i7-8700K is a bit faster. Our article includes only a few selected applications so the difference might change with other scenarios. Nevertheless it's interesting to see that the i7-5820K is still pretty competitive. We are quite surprise since the Core i7-5820K is based on Haswell-E architecture and it's already four years old.

If you still own a LGA2011-3 platform (like me!) and you would like to update your system, then the Core i7-8700K might be a good solution. As you might know, the Core i7-8700K is compatible with both Intel Z370 and Z390 chipsets. If you upgrade now, you could swap your i7-8700K for a i9-9900K in a later stage when the used market will offer some good deals. In other words, the Intel Z370 chipset offers some longevity. Furthermore you might save some money on power consumption since the difference is pretty solid.

On the other hand, you could overclock a bit your Intel Core i7-5820K and gain some extra performance. The TDP on this generation was pretty high, however the IHS is soldered and you won't have big issues in terms of temperature. With a golden sample you might hit 4.8GHz on daily use, with a normal chip we believe you could stay around 4.4-4.5GHz. The power consumption will still play some role in this game.

At the moment the Intel Core i7-8700K is available on Geizhals for 420 Euro and a good motherboard will costs around 150-200 Euro. Checking on, we find the Core i7-5820K sold for 200 Euro and the Core i7-8700K available for 300 Euro. These prices are rather good and they could justified an upgrade.

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Core i7-5820K vs Core i7-8700K - 2D Performance - CPUs Content Creation - Reviews - ocaholic