There are significant performance regression on metal/compute/hlslcc when compared to trunk or 5.4/release:

With modified 'Viking Village (2014)' project:

(~75/93) vs (56/37) - (metal/compute/hlslcc) vs (trunk) - GPU/CPU

on GPU, all shaders are way slower (besides gpu frame looks more or less the same).

on GPU, according to Unity’s profiler, Camera.Render->Drawing is around ~26ms vs ~20ms. the rest is used up by Gfx.WaitForPresent 55ms vs ~35ms.

With the project from case 761024:

there is no significant regression in GPU frametime, but a similar regression on CPU.

This is not reproducible with all projects i.e Survival Shooter. Standard shader performance and mobile torture test results also seem to be similar.

See :
https://docs.google.com/spreadsheets/d/1jblawHwE4XGTERJviUESAbLXTj3l4KDuKj_moMHcO3c/edit#gid=2040315717
for details and links to projects

Tested with:

Version 5.5.0a5 (fd625b0c0421)
Tue, 26 Jul 2016 08:45:37 GMT
Branch: trunk

Version 5.5.0a5 (d23d0dd92b49)
Wed, 27 Jul 2016 12:36:09 GMT
Branch: metal/compute/hlslcc