Literally three results on google for this word, congratulations!
Looking good, did you laser-cut those?
Do you have a normal ITX board to test it?
Maybe the PCIe Port is the problem.
With no riser you have only 25W on thin itx and with your special powered riser you maybe have 75W but only if it work as expected. Some weeks ago I read an artical about the special powerdraws of the PCIe port on different gpus. If i remember right different gpu generations draw differen power values on 12V and 3,3V.
You are using FurMark, which is known to cause unrealisticly high loads. It often leads to throttling with more recent cards. I would advise on staying with Heaven benchmark.
If the peaks are well over the sustainable power, a large enough set of condensators might do the trick, but you probably know more about that than I do. The issue could be in the design of the power brick, as it is probably not specced for these kinds of peaks, while ATX PSUs probably do.
If so, that's not a good precedent for future cards, which will be using even more active power management than Maxwell 2 and Fiji.I'm really starting to feel it has something to do with how the GPU is loaded.
Extremely light loads = fine
Extremely heavy loads = fine
moderate loads = fail
No need to be sorry though Stuff like that happens all the time. By the way, are you running those apps full-screen or windowed ? You should run these windowed if not.
I would still recommend trying other test apps to get more perspective on the matter. 3DMark is a good option.
If so, that's not a good precedent for future cards, which will be using even more active power management than Maxwell 2 and Fiji.
It does make sense that laptop PSUs may not handle wildly varying power draw. In almost all cases, they're going to be merely charging a battery, from which the laptop will be drawing a varying load. Maybe adding a transient decoupling capacitor to the final output stage (or beefing up the existing one, or adding one after the output on that lovely adapter board) will keep the load stable enough for laptop PSUs to cope with.
It seems the most logical that it is the peak power consumption, looking at the results. I'm really interested in this little project as a part of the case, I hope you'll see this through and that it can became a 100% stable solution, I have faith that you can achieve this.
Do you still have the powered riser from H2O-micro? As dondan said, the problem might be that the card is trying to draw more than 25W from the PCIe slot, with the powered riser you could easily test that assumption.