different benchmark result

[EhsanVahab]

I have two models, both of them are exactly the same. when I executed benchmark of NCNN of darknet2ncnn(exists on darknet2ncnn/ncnn/build/benchmark/) on Raspberry pi 3b, I got 150ms however with latest version of original NCNN's repository(https://github.com/Tencent/ncnn) I got 350ms.

I got hesitated. what is the problem and which one is really true? I've built NCNN from original repository with following command :

cmake -DCMAKE_BUILD_TYPE=Release -DNCNN_VULKAN=OFF -DNCNN_SYSTEM_GLSLANG=ON -DNCNN_BUILD_EXAMPLES=ON -DCMAKE_TOOLCHAIN_FILE=../toolchains/pi3.toolchain.cmake -DPI3=ON .. and built NCNN of darknet2ncnn with: cmake ..

the NCNN's version of darknet2ncnn is the 2020-03-06.