AMD power limit

[aezakmi]

Guys I have an ASUS 470 8GB and, as always, I'm looking to overclock it just for the sake of doing it.

 

Now, I know how the power limit settings work in nvidia cards, but what about AMD? I'm using afterburner to OC with the Extend official overclocking limits, Disable ULPS and  Reset display mode on applying unofficial overclocking options enabled.

The default clocks are 1270 and 1650 and these would be my main overclocks so far:

 

1300+12mV / 1650 = Furmark stable for an hour

1350+12mV / 1700 = Furmark crashes after 10 minutes

1350+18mV + 10% Power Limit / 1700 = Furmark stable for an hr

1400+26mV + 10% / 1750 = crash after 15 mins

 

now... shouldn't be my 10% increase be 10% over the default limit? let's say 100 + 10% = 110? I know it's not 100 that was just an easy example.

Afterburner shows 120-130W at stock speeds and 128-135 with the overclock and 10%... shouldn't be between 132 and 143? Because 128 is clearly not 120+10%... so, what's wrong? I don't want to pump more voltage into it before sorting this out.

 

I've also noticed I can only increase mV by 6 and not by 1 and this could be a problem in fine tuning my OC.

[TheRandomness]

It’s a power limit, the card can draw up to that amount. Raising the power limit means the card will be able to draw more current and therefore more power. Also, no need to be so conservative on the voltage. 

[Stefan Payne]

The Power Limit is a hard one wich doesn't allow more than it is supposed to.

The chip clocks down when the Power Limit is reached.

[O9B0666]

58 minutes ago, Stefan Payne said:

The Power Limit is a hard one wich doesn't allow more than it is supposed to.

The chip clocks down when the Power Limit is reached.

Don't some chips start to clock down slowly when you get near the set limit? like say 2000ghz clock obviously once you start getting closer, your reaching your say set limit of 100, so upping your power to say 150 lets it get to 2000 on on the clock cause it still has more power it can use? Hopefully i asked that right. 

[Tam3n]

If you crash, it simply means too low Vcore, or might be too high memory clocks. Rising the power limit only helps you to avoid throttling under heavy load. In other words, if you see your clocks falling below what you set in after burner under heavy load, you need to raise your power limit. I always just set it to max and forget it. For high overclocking (once you have maxed default limits) you might need to edit GPU bios or registry powerplay tables, but this generally not for 24/7 use...

 

I might add that Furmark is not a good GPU stability tester for real word. It's only good for testing the cards power delivery. Use Unigine Heaven, Valley & 3Dmark Fire Strike or TimeSpy instead. Look for artifacts and glitches in these programs to determine stability, and then of course go and play your games.

[aezakmi]

14 hours ago, Tam3n said:

If you crash, it simply means too low Vcore, or might be too high memory clocks. Rising the power limit only helps you to avoid throttling under heavy load. In other words, if you see your clocks falling below what you set in after burner under heavy load, you need to raise your power limit. I always just set it to max and forget it. For high overclocking (once you have maxed default limits) you might need to edit GPU bios or registry powerplay tables, but this generally not for 24/7 use...

 

I might add that Furmark is not a good GPU stability tester for real word. It's only good for testing the cards power delivery. Use Unigine Heaven, Valley & 3Dmark Fire Strike or TimeSpy instead. Look for artifacts and glitches in these programs to determine stability, and then of course go and play your games.

I did heaven, valley and superposition 3 times each today, works good

 

18 hours ago, TheRandomness said:

It’s a power limit, the card can draw up to that amount. Raising the power limit means the card will be able to draw more current and therefore more power. Also, no need to be so conservative on the voltage. 

max core voltage is +100 and 25% for the power limit, I went easy on it because I don't want to overheat the card, at stock clocks the max temp was around 65C, with the overclock I'm hitting 75C after a while

[TheRandomness]

36 minutes ago, aezakmi said:

I did heaven, valley and superposition 3 times each today, works good

 

max core voltage is +100 and 25% for the power limit, I went easy on it because I don't want to overheat the card, at stock clocks the max temp was around 65C, with the overclock I'm hitting 75C after a while

95C is the max safe temperature to run 24/7 at. Those temps are fine.

[aezakmi]

2 minutes ago, TheRandomness said:

95C is the max safe temperature to run 24/7 at. Those temps are fine.

thanks

 

1400 is the absolute max for the core with 50mV and 18% limit (tried 25% but makes no difference) artifacts start at 1401 which sucks.

mem can do 2000 for the moment