Thanks for all the information!
But... I still want reply of my original question
I am a very curious person, and the nature of my coutnry (Brazil) where I can't get lots of stuff, means I am used to hacking around (I am building my own chassis for my build, and I will build my own fan controllers, and I convinced Nuvoton to give me the datasheet for my mobo super i/o chip, although I am not sure yet what I will do with that one).
This is why I want to actually poke around the card, see if I can get values out of it. For example in the datasheet I linked I noticed it has registers that are triggered when voltage protection happens, I would love to know how to read that by software.
About my card. I have a Sapphire 380X, Tom's Hardware tested it.
During Metro 4K loop, the average power from PCIe cables (not the slot) was 141W, total (the entire PCB draw) average was 191W
Furmark it reached average from PCIe cable of 186W, and total average was 252W
So, the number you gave me earlier, matches both the total draw during the Metro loop, but also the PCI-e cables draw during Furmark.
So what one was it?
Also, why Furmark even with throttling seemly can still draw that much power? Or the power saving behaviour then was different? (seemly the newer Crimson releases REALLY clamp down the power controls, compared to Catalyst).
And the Watts I see reported as "VDDC in" on Sapphire Trixx for example are what, GPU only? (for example a bug in Mad Games Tycoon today, made the card behave like if a power virus program was running, mail terrible coil whine, the "VDDC in" power on Sapphire Trixx was during that event averaging 120W)
Now back to the review...
On this page:
They test OC, conclude OC doesn't work, because stock already throttles a little.
The behaviour I see from my 380X, is like the graph on the top with the drivers 16.6.1 + 20% power limit, with the "red" version with default voltage, and the "blue" version with -40mv (with drivers 16.4.x it went CONSTANTLY between 1040mhz and 600mhz... AMD told me to test Catalyst 15.11.1, didn't had time to do that yet).
And similarly, running OCCT results in a graph like the second one, but without the "ramp" down, since it is not thermal related, and happens immediately (also the peak temperature during OCCT is about 65C with fans at 70%)
OCCT at 1024x768 (my test screen resolution), on stock settings achieve about 550fps (with error checking enabled). During a test today with +20% power limit, it hit 590fps, and undervolted to -40mv it reached 605fps, and the clock graph looked a lot less "spiky", and more like a solid line at about 980mhz
I saw that in the registry there are some PowerPlay related controls, that Crimson and Catalyst write to the registry in a different manner, and people call it "Crimson Power Saving", I will see what happen if I tweak that AFTER I install a new PSU (if I accidentally draw a humongous amounts of watts I don't trust that my current PSU has enough protections about it).Edited by OrSpeeder - 7/5/16 at 8:25pm