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HWBOT x265 Benchmark

Published: (last update )

World's first x265/HEVC user-friendly benchmark. Featuring hardware detection based on CPU-Z and realtime monitoring. Integrated with HWBOT to allow competitive benchmarking.


HWBOT x265 Benchmark is based on the open source x265 encoder (http://x265.ru/en/). It can take advantage of modern CPUs instructions set and multithread support is also very good. However this benchmarks is also capable of running even on as old processors as AMD Athlon or Intel Pentium III. Of course on the legacy hardware the encoding time is rather long. There are two presets available - 1080p and 4k. The main goal of both of them is to convert H264 source video to H265/HEVC and measure average fps.


This benchmark can be very stressing for your CPU. Both power usage and temperature can reach much higher levels than other benchmarks or software. Use at your own risk.

Update 7th December 2018 - It was discovered by HWBOT members that running the 4k preset on highly overclocked Intel processors using extreme cooling methods can in rare cases result in destruction of the CPU. While the number of dead CPUs is not big, the chance of killing your CPU is higher with x265 Benchmark than with other popular benchmarks.
Affected processors are Haswell and later. There is one case of dead Ivy Bridge Core i7 3770k. There are no reported incidents when using air / water cooling. Also no reported problems when using AMD processors with any cooling mehod.

Possible cause of this could be extreme power consumption of said processors combined with rather long running time of the 4k preset.

Use extreme caution when using x265 for extreme overclocking. Use at your own risk.

HWBOT x265 main window

Now to describe the new Benchmark options:
1. Benchmark type - 32bit or 64bit encoder. Use 64bit if possible, it is faster, on some platforms by quite a big margin.
2. Priority - priority of the encoder process, not much to say here.
3. Pmode - enables better thread utilization, improves performance on some platforms. Also can slow things down a bit, depends on CPU type.
4. Overkill mode:

For even better multithreading support it is possible to activate the overkill mode. Two or more (up to 8 in the current version) instances of the encoder will run simultaneously and when all of them are finished, the final score is sum of all sub-scores minus small compensation to avoid score gain by uneven compute time. If the sub-scores time variability is bigger than 5%, the overkill run is considered invalid and no score is generated.

The HWBOT x265 Benchmark implements security features which should block any attempt to replace external components of the benchmark (source videos, ffmpeg, x265 encoder) or score manipulation. There are two ways to upload score to HWBOT. Save the data file which contains screenshot and all necessary information. Or direct online submission from the benchmark (currently in development, will be ready in the final version). Also this benchmark should be safe to run using Windows 8(+) - when HPET is active.

Minimum system requirements:
AMD Athlon / Intel Pentium III
512 MB RAM (1080p) / 1.5 GB (4K)
1 GB free HDD space
Windows XP SP2

Recommended system requirements:
AMD FX / Intel Core 2 Quad 45nm (with SSE 4.1)
2 GB free HDD space
Windows 7 x64 (SP1 for AVX support)

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