Originally Posted by tolis626
Testing without Freesync was the first thing I tried. It makes no difference. Turns out it's directly related to my GPU voltage. If I go above +25mV in Afterburner (Above my stock 1.275V VID), it will start going black when it first transitions from 2D to 3D clocks. Sometimes it will come back, sometimes it won't. The higher I go, the worse the problem becomes. But if I limit the GPU to 1140MHz and +25mV it doesn't happen much, if at all. Weird, but hey, I'm missing like 10-20MHz from my previous 24/7 overclock.
Well, I really don't understand much about that Wattman memory voltage to be honest.
Doesn't seem to be doing much with the 390x though.
Regarding the different MVDDC values, that may actually be the culprit. Bad thing is, I have no idea about BIOS modding, especially "advanced" stuff like using Hex editors and such. I'd love to try going higher though. With that said, right now I can't afford this GPU dying on me, so I'd be pretty reluctant, but if I get another GPU, I could definitely see myself giving this a go for fun. The 390x has served me long and well, but it may have one last trick up its sleeve it seems.
Ok, weird, I have no idea of what can be causing the problem.
About the wattman memory voltage, if ti is working fot the 390 I don't have a 390 to test, maybe like BradleyW
said, it could helpto solve your problem. Because as it is a lower limit to to the core voltage for a memory clock, it can help in transitions from 2D to 3D.
I did some test in the past with the wattman memory voltage for my 380 (now is broken, but not for testing this), and the weird thing about it is that with memory timings mod it can be lowered and not cause any problem. But without it lowering it can cause black screens. Also I have tested to lower it to my new 590, but I get black screens.
I don't know how to do a proper timing mod, I don't have these tecnical skills. But this is the mod I did for my 380 with H5GC4H24AJR memorys (some 390 have the same memoryes, so it coul work for them), for 1500 and 1625 strap, and was working ok with low wattman memory voltages. :
And the values for it that I get with this Vento041 tool
The stock timings for the 1500 strap are:
And the values for if are:
Maybe somebody with timings mod skills could test this and say why these timings can help to lower the wattman memory voltage.
As memory timings mod can cause the gpu to brick, is not recomende to do this if you don't have a dual bios gpu or advanced bios flashing skills.
As your 390 performance is excellent nowadays, don't put it in risk.