PCMark is described as 'industry standard benchmark for Windows PCs and Android devices'. There are more than 10 alternatives to PCMark for a variety of platforms, including Windows, Mac, Linux, Android and iPhone. The best alternative is AIDA64. It's not free, so if you're looking for a free alternative, you could try UserBenchMark or Cinebench. Other great apps like PCMark are 3DMark (Paid), Geekbench (Paid), UNIGINE Benchmarks (Freemium) and Furmark (Free).
Linpack is a benchmark and the most aggressive stress testing software available today. Best used to test stability of overclocked PCs. Linpack tends to crash unstable PCs in a shorter period of time compared to other stress testing applications.
Bringing the popular GFXBench benchmarking suite to desktop OpenGL and OpenGL ES 3.1 plus Android Extension Pack, GFXBench 4.0 enables measuring mobile and desktop performance with advanced graphics effects and increased workloads.