Intel Core i7-8700K And Core i5-8400 Review: Coffee Lake - More Cores, Performance And Value

Intel Core i7-8700K And i5-8400 - JetStream, LAME MT, And Blender

Next up, we have some numbers from the JetStream Benchmark Suite developed by WebKit. The JetStream Benchmark Suite uses a wide array of latency and throughput benchmarks to evaluate JavaScript performance, and all of the results are tabulated with roughly equal weighting. The benchmark measures both metrics of traditional JavaScript programming styles used on websites as well as new JavaScript-based technologies used on more modern, rich web applications. Scores in this benchmark are an indicator of the performance users would see when browsing and running advanced web applications.

JetStream JavaScript Benchmark
JavsScript Performance Testing

All of the systems were tested using the latest version of Microsoft's Edge browser, with default browser settings, on a clean install of Windows 10 Professional x64.


The Core i7-8700K takes the lead in the JetStream benchmark as well. Single-threaded performance is key in this benchmark, and as such, its high clocks and use of Intel's latest cores propel the 8700K into the lead.

Audio Conversion and Encoding
In our custom LAME MT MP3 encoding test, we convert a large WAV file to the MP3 format, which is a popular, day-to-day use case for many end users, to provide portability and storage of their digital audio content. LAME is an open-source mid to high bit-rate and VBR (variable bit rate) MP3 audio encoder that is used widely around the world in a multitude of third party applications.

In this test, we created our own 223MB WAV file and converted it to the MP3 format using the multi-thread capable LAME MT application in single and multi-thread modes. Processing times are recorded below, listed in seconds. Shorter times equate to better performance.


We saw more of the same in our custom LAME MT benchmark. This test uses either one or two threads, so the additional resources in many-core processors go unused. The super-speedy cores in the Core i7-8700K, however, rip through this test. The Core i5-8400 performed very well here too.

3D Rendering Benchmark

Blender is a free and open source 3D creation suite that can handle everything from modeling, rigging, animation, simulation, rendering, compositing and motion tracking, even video editing and game creation. It has a built-in benchmarking tool that will track the time it takes to complete rendering a particular model. We used a CPU-focused BMW model for these tests here...

As we move into some more heavily-threaded benchmarks, things get very interesting. The Core i7-8700K's architectural advantages and high-frequencies allow its 6 cores to overtake the Ryzen 7 1800X's 8 cores by about 20 seconds. Heck, the Core i7-8700K even manages to overtake the Core i7-6900K. The 10-core Core i9-7900X, however, holds onto a commanding lead (let alone the higher-core count Core X processors or Threadripper, which aren't listed here).

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