If I set power limit to 100% on a 100W TDP card it will never draw more than 100W right?

[17030644]

and if I could set it to let's say, 200% can the card surpass the 150W "limit" that the PCIe slot + PCIe 6 pin connector offer?

 

and does that power limit take into account 3.3V rail power consumption?

[Electronics Wizardy]

so there is peak power and there is average power, peak will be higher than the rated max.

 

The power limit won't cause a issues if you pull 151w, it won't cutt off power.

 

What are you trying to do here? 

[17030644]

4 minutes ago, Electronics Wizardy said:

so there is peak power and there is average power, peak will be higher than the rated max.

 

The power limit won't cause a issues if you pull 151w, it won't cutt off power.

 

What are you trying to do here? 

just wondering

 

again if my card is 100w tdp and i set power target to 100% there's no way it goes above 100W peak power consumption right?

[Electronics Wizardy]

1 minute ago, 17030644 said:

just wondering

 

again if my card is 100w tdp and i set power target to 100% there's no way it goes above 100W peak power consumption right?

no it will go over 100w in peak power for short periods of time. The power usage isn't very flat if you putt out a scope.

[Jurrunio]

15 minutes ago, 17030644 said:

and if I could set it to let's say, 200% can the card surpass the 150W "limit" that the PCIe slot + PCIe 6 pin connector offer?

that's why no cards come with a 200% power target BIOS from the factory.

 

16 minutes ago, 17030644 said:

and does that power limit take into account 3.3V rail power consumption?

No, graphics cards dont need this voltage. They dont even bother transforming 3.3V power to anything the card needs because it's easier to do it from the 12v rail instead.

 

8 minutes ago, 17030644 said:

again if my card is 100w tdp and i set power target to 100% there's no way it goes above 100W peak power consumption right?

No, it will certainly spike past 100w. It can only make sure it doesnt draw past 100w sustained power.

[dizmo]

TDP isn't a power draw metric, it's the maximum amount of heat that can be dissipated by the component.

[17030644]

13 minutes ago, Electronics Wizardy said:

no it will go over 100w in peak power for short periods of time. The power usage isn't very flat if you putt out a scope.

thanks

6 minutes ago, Jurrunio said:

that's why no cards come with a 200% power target BIOS from the factory.

 

No, graphics cards dont need this voltage. They dont even bother transforming 3.3V power to anything the card needs because it's easier to do it from the 12v rail instead.

 

No, it will certainly spike past 100w. It can only make sure it doesnt draw past 100w sustained power.

thanks, yeah ik that is rather unrealistic but I mean isn't there any card that has its power limit slider higher than whan the connectors are allowed to pull? Let's say a 200W card with a 120% power limit (that's 240W max) but only has an 8 pin plug? (That's 225W max theorical limit)

[17030644]

1 minute ago, dizmo said:

TDP isn't a power draw metric, it's the maximum amount of heat that can be dissipated by the component.

I know but I saw that power limit is based on TDP, if the power limit es 100% that's 100% of the card's TDP correct me if I'm wrong

[Electronics Wizardy]

3 minutes ago, 17030644 said:

thanks

thanks, yeah ik that is rather unrealistic but I mean isn't there any card that has its power limit slider higher than whan the connectors are allowed to pull? Let's say a 200W card with a 120% power limit (that's 240W max) but only has an 8 pin plug? (That's 225W max theorical limit)

Yea you can pull more power from a card then the pcie spec allows

 

But the molex power cables that are used for pcie power are rated for more than double than the pcie spec allows.

[17030644]

3 minutes ago, Electronics Wizardy said:

Yea you can pull more power from a card then the pcie spec allows

 

But the molex power cables that are used for pcie power are rated for more than double than the pcie spec allows.

So it's safe right?

 

23 minutes ago, Electronics Wizardy said:

no it will go over 100w in peak power for short periods of time. The power usage isn't very flat if you putt out a scope.

 

16 minutes ago, Jurrunio said:

 

 

No, it will certainly spike past 100w. It can only make sure it doesnt draw past 100w sustained power.

Is there a way to know by how much it could spike?

[Electronics Wizardy]

2 minutes ago, 17030644 said:

So it's safe right?

Yea don't worry about this at all.

 

2 minutes ago, 17030644 said:

s there a way to know by how much it could spike?

Get a current shunt and a scope. But don't worry about this at all.

[17030644]

2 minutes ago, Electronics Wizardy said:

Yea don't worry about this at all.

 

Get a current shunt and a scope. But don't worry about this at all.

It matters if you don't know the real capabilities of your power supply and want to overclock without tripping the OCP circuit on your power supply or burning it out I guess

[Electronics Wizardy]

1 minute ago, 17030644 said:

It matters if you don't know the real capabilities of your power supply and want to overclock without tripping the OCP circuit on your power supply or burning it out I guess

Peak power can go over the ratings of a psu, there are capacitors that are designed to handle these peaks, and there for very short periods of time.

 

Whats your config?

[Jurrunio]

14 minutes ago, 17030644 said:

thanks, yeah ik that is rather unrealistic but I mean isn't there any card that has its power limit slider higher than whan the connectors are allowed to pull? Let's say a 200W card with a 120% power limit (that's 240W max) but only has an 8 pin plug? (That's 225W max theorical limit)

There is only 1 that I'm aware of, the AMD R9 295X2. 500W TDP, only has a pair of 8pin connectors.

 

It's still safe though. Each PCIe power cable coming out from the power supply can handle 324W power each, which means the R9 295X2 is out-of-spec but still safe as long as the two connectors stem from different cables connected to the PSU