Recently, I have experienced many different platforms for H265 playback. All my platforms do not provide support for hardware decoding capabilities for H265. But I found something charming, something disappointed. The most unbelievable one is that Celeron M1000, an Ivy Bridge processor, working only at 1.8GHz maximum, but it could playback H265 video smoothly with comparably low CPU consumption, less than Pentium G6950 (2.8GHz), Core 2 E4600 (2.4GHz) and Pentium E5200 (2.5GHz). Those latter processors could also playback it smoothly. Those four Intel processors decode such video files without any hardware acceleration from GPU.
As to AMD entry level processors that I tested are AMD Sempron X2 180/190, AMD Athlon II 245/250 and A4-3300/3400, none of six processors could playback the same video file at an acceptable performance. But as to A4-3300/3400, I found some workaround, that is to find some a decoder which could utilise the internal GPGPU to accelerate the process of decoding H265. Strongene OpenCL H.265/HEVC Decoder for Windows is a good choice, I tested it on platform of A4-3300/3400. The performance is acceptable, and the CPU consumption is acceptable too.
I've also tested on AMD A4-5300 processor yesterday, this processor is excellent for decoding H265 by processor itself. When using this Chinese OPENCL decoder, the CPU consumption turns to be very high, and the performance turns to be worse. The reason might be that the overhead to set-up OpenCL environment consumes more computing resources than merely decoding by the processor itself.
Sempron X2 180/190 and Athlon II 245/250 are not strong enough to decode H265 1080p, I tried to add an NVidia 8800GT external GPU attaching to such systems. This external GPU lacks the capabilities to decode H265, but its CUDA core also support OpenCL computing. After using this decoder, H265 1080p video files could also be replayed smoothly at acceptable performance.