Originally Posted by Arkanon
The power limit in VBE
Marked the thing i was talking about, sorry for the confusion. Whenever i raise those values my card becomes instable with my overclock of 1275/1500 and games hang nearly instantly. As far as I know, raising the power limiter or TDP or whatever it's called exactly should give me some more overclocking headroom due to the fact the card is allowed to draw more power or am I wrong?
I just made a post a week or two ago about this. I'll try and sum it up.
The power limit doesn't actually do anything or affect the TDP of your card because it's all in software. The power draw of the card is determined by it's power connectors (and as someone corrected me, the PCI-E slot). I don't know what card you're using but generally a 270X takes two 6-pins and a 280X takes an 8-pin and a 6-pin. 8-pin power connectors provide 150w and 6-pin power connectors provide 75W in addition to the 75W from the PCI-E slot. This means that a 270X will have 150W from the power connectors and 75W from the PCI-E slot for 225W. A 280X will have 225W from the power connectors and 75W from the slot for 300W total. Of course, your system can draw more power under load, my R9 290 has been shown to draw as much as 400W under load with a high VDDC voltage and 50% power limit.
Anyway, the point is that nobody really knows for sure what the power limit does, because regardless of what you set it to, the cards power draw is determined by the connectors and the slot. This determines it's TDP. Raising the power limit influences stability during overclock, but most importantly it reduces clock throttling under load. The best way to test this is to overclock, raise the voltage, with a power limit of 0% and run something like Unigine Valley with a GPU-Z sensor log. If you see your card unable to maintain the clocks you set, and it downclocks, in the sensor log then you know you need to raise the power limit. Raising it to 20% should be more than enough, but newer cards can go to 50% by default. There is nothing wrong with maxing out the slider and running the card with 50% power limit, because all this really does is tell the software and the drivers not to throttle the card under load. It's all done in software, from what I've seen many people say here. So, it still doesn't really affect the TDP of the card or it's power draw at all, other than the card will draw more wattage over a prolonged period of time since it's not downclocking or throttling.
Really, I have no solution to your problem and neither does anyone else here, other than to tell you that if it ain't broke don't fix it. If you can run your overclock fine without messing with the power tune, but it crashes when you edit the powertune, then just DON'T EDIT THE POWERTUNE and you'll have no problem with your overclock.
I have no idea what card you have and neither does anyone else because you don't have a rigbuilder and you haven't stated it. This makes it hard to help you. Click rigbuilder in the top left, fill out your system specs, then go to your profile -> edit signature -> show off stuff in my signature -> select the rig in the drop down box.
Hope this helps.