GTX1080 G1 Memory downclocks during GPU compute

[Sigtran]

During games, no issues, GPU boost works ok, and memory stays at 1251MHz (10GHz effective).

However, during intensive GPGPU computing, GPU boost still works, but memory downclocks to 1128MHz (around 9GHz effective). This is NOT what I have expected, nor anywhere this behavior has been "advertized".

Depending on GPU load type, GPU-Z states PerfCap reason as Util (if GPU load high) or Vrel (memory load high).

Any explanations? Looks to me as a (BIOS?) bug, as I have not found anywhere this as a feature...

Simplest way to provoke this is by using  gpumemtest:
http://www.programming4beginners.com/gpumemtest

[Sigtran]

Let me reply to myself. After some investigation, seems this is a "feature" of Nvidia built into drivers and affecting Pascal (10x0 series), and also previous Maxwell (9x0 series) that if pure GPU compute is going on (so no graphics output), power state is set as P2, and not a P0 (which is the 3d maximum performance state). Why nVidia is doing so, it is a question...