Why can I not stop my 390 Xfire from throttling on the core and voltage?

[TonyTurbo78]

Hi guys, this is really starting to annoy me.

When gaming, in MSI Afterburner overlay, I can clearly see my core clocks and voltage fluctuating. I have set 1050MHz on the core for both cards, yet 90% of the time I see they fluctuate between 1050MHz and 950MHz, with the voltage fluctuating as well. When I bench, the clocks stay where they should with no fluctuation at all, it's just when I game and gpu usage drops below 90% on each card. The bigger the usage drop, the bigger the core drop and voltage drop, surely this isn't right to have the core clocks dropping just because crossfire scaling drops below 90% on both cards. Any ideas why they would be doing this? I've tried removing any frame cap in games to let them run as fast as they can, I've put 50% power boost in Afterburner, I've reinstalled the latest version of MSI AB, but nothing seems to lock the core at 1050MHz unless I get more than 90% usage on the cards.

Please help me, doing my swede in here. These are my MSI AB settings

Spoiler

 

[This never ends well]

if you haven't done this saving a profile for your stock clocks and then go to setting's, profile then set 3dclocks to your stock clocks in AB, then try a game to see if your clocks throttle down

 

[TonyTurbo78]

nope, still the same. Unless I get more than 90% usage on both cards, my core clocks drop to under 1000MHz.

 

[nails666]

Hi Tony, I saw your post in the driver thread about this and I was having exactly the same issue with my 295x2 in The Witcher 3 and World of Warcraft. I have just tried out one of the suggestions in that thread to change the 'Unofficial overclocking mode' at the bottom of the settings screen there from 'disabled' to 'without powerplay support' and that does seem to have sorted it now. Tried the Witcher and sure enough mine clocks stayed locked at 1020MHz.
However, the downside of this is that the clocks on both cards stay locked at that speed all the time, i.e. even when just sitting at the desktop both cards are still at 1020MHz, no downclocking when idle so more power usage and higher temps. Now I'm not really worried about the power usage and even the temps, it just means a higher idle temp but load temps shouldn't really change so I'm going to stick with it for now and see if maybe future drivers fix it.

 

[TonyTurbo78]

hmmmm tried that Nails, ran Witcher 3 and I was getting 20% usage on both cards, with the core clocks at 300MHz each lol. Maybe an issue with MSI Afterburner and new 3 series AMD cards? Could they not be supported in some way?

 

[nails666]

Ah right, not quite the desired effect then That almost sounds as if they were stuck at idle clocks, what speeds did they go to at the desktop when you set that mode?

 

[TonyTurbo78]

core clocks went to 300MHz at desktop.

 

[nails666]

Hmm, will they change at all if you adjust the overclock settings in AB after that point? If not them I'm out of ideas I'm afraid, may be as you say that the newer cards have some differences at a driver level

 

[TonyTurbo78]

i'll just let them throttle, cant be arsed to fiddle anymore. It's not like im seeing any frame drop or anything, I was just curious why these cards are doing it where as my old 7950 crossfire wasn't.