how to undervolt a gtx 980 reference card?

[squallypo]

i wanna know if theres a way to undervolt this card to keep the wattage usage lower.

i was planning to use msi afterburning but when i tried to do ctrl+F it doesnt show the custom curve for the voltage.

perhaps someone can help me out with this.

[Mick Naughty]

Could lower the power. 

[Frankenburger]

Lower the power target and raise the core clock until you hit your desired results. It won't be as specific as editing the clock/voltage curve, but it'll basically achieve the same thing in the end.

[squallypo]

1 hour ago, Frankenburger said:

Lower the power target and raise the core clock until you hit your desired results. It won't be as specific as editing the clock/voltage curve, but it'll basically achieve the same thing in the end.

so like this?

[Frankenburger]

15 minutes ago, squallypo said:

so like this?

Exactly

[squallypo]

may i ask, why do i need to raise the core clock? isnt that like overclocking it ?

[Frankenburger]

24 minutes ago, squallypo said:

may i ask, why do i need to raise the core clock? isnt that like overclocking it ?

Undervolting = restricting power while raising the default clock curve to maintain performance

 

Specific power points have fixed clock speeds. If all you do is lower the power target, then you are reducing power consumption while also using a lower clock speed.

 

For example, a default clock/voltage curve may tell your GPU to run at 1400MHz at 900mv. If your card uses 1050mv at 100% and runs at 1800MHz, and you want to maintain a comparable clock speed, you need to tell the GPU to run faster, otherwise you'll be running at 1400MHz.

[squallypo]

2 minutes ago, Frankenburger said:

Undervolting = restricting power while raising the default clock curve to maintain performance

 

Specific power points have fixed clock speeds. If all you do is lower the power target, then you are reducing power consumption while also using a lower clock speed.

 

For example, a default clock/voltage curve may tell your GPU to run at 1400MHz at 900mv. If your card uses 1050mv at 100% and runs at 1800MHz, and you want to maintain a comparable clock speed, you need to tell the GPU to run faster, otherwise you'll be running at 1400MHz.

i think i understand, but trying to keep my power consumption lower, while raising the core clock as i added 100+ wont it be damaging the gpu ? thanks for taking your time explaining this to me.

[Frankenburger]

12 minutes ago, squallypo said:

i think i understand, but trying to keep my power consumption lower, while raising the core clock as i added 100+ wont it be damaging the gpu ? thanks for taking your time explaining this to me.

The only thing you risk is system instability, which you can correct if you undervolt incorrectly. The only way to damage a video card using MSI Afterburner is if you overvolt it to unsafe levels, which is basically an impossibility since the power target is locked.

 

Undervolting is perfectly safe. Just make sure you don't allow the undervolt to apply automatically until you know it's stable. If anything, undervolting may increase GPU longevity. Less power means less electricity running through the GPU, means less heat, means less work on the cooler. Increasing the core clock won't change that.

[squallypo]

1 minute ago, Frankenburger said:

The only thing you risk is system instability, which you can correct if you undervolt incorrectly. The only way to damage a video card using MSI Afterburner is if you overvolt it to unsafe levels, which is basically an impossibility since the power target is locked.

 

Undervolting is perfectly safe. Just make sure you don't allow the undervolt to apply automatically until you know it's stable. If anything, undervolting may increase GPU longevity. Less power means less current running through the GPU, means less heat, means less work on the cooler. Increasing the core clock won't change that.

i was checking gpuz while testing a game with the 78% power limit i didnt added the 100+ core clock at the time (I THINK), i noticed these values.

having limited the power shouldnt the wattage be lower? although that was max not nescesary stayed at it.

[Frankenburger]

4 minutes ago, squallypo said:

i was checking gpuz while testing a game with the 78% power limit i didnt added the 100+ core clock at the time (I THINK), i noticed these values.

having limited the power shouldnt the wattage be lower? although that was max not nescesary stayed at it.

165w is generally what GTX980's consume under load, so there's definitely a decrease in power, especially if the average power consumption is below 161w. Though I've seen GPUz report weird values when using MSI Afterburner to undervolt. My suggestion would be to reference Afterburner's sensors to verify everything is running as it should.

[squallypo]

7 minutes ago, Frankenburger said:

165w is generally what GTX980's consume under load, so there's definitely a decrease in power, especially if the average power consumption is below 161w. Though I've seen GPUz report weird values when using MSI Afterburner to undervolt. My suggestion would be to reference Afterburner's sensors to verify everything is running as it should.

last question i make i dont wanna trouble you more, what would be the values i should be getting with the current power limit of 78 with this card on msi afterburner? specificly the gpu voltage values

[Frankenburger]

12 minutes ago, squallypo said:

last question i make i dont wanna trouble you more, what would be the values i should be getting with the current power limit of 78 with this card on msi afterburner? specificly the gpu voltage values

I honestly can't say. Power Target and voltage don't scale linearly with each other. Also, there's slight variations in each processor that could affect efficiency. I believe the GTX980 uses around 1050mv at stock, but I could be wrong. Though of it does, I would expect it to be around 900mv.

[squallypo]

3 minutes ago, Frankenburger said:

I honestly can't say. Power Target and voltage don't scale linearly with each other. Also, there's slight variations in each processor that could affect efficiency. I believe the GTX980 uses around 1050mv at stock, but I could be wrong. Though of it does, I would expect it to be around 900mv.

i see ive seen it escalate over 1206v on the gpu voltage in msi afterburner even with power limit, but ill test around and disable  gpuz incase its fluctuating with it, thank you very much for your help.

[Frankenburger]

2 minutes ago, squallypo said:

i see ive seen it escalate over 1206v on the gpu voltage in msi afterburner even with power limit, but ill test around and disable  gpuz incase its fluctuating with it, thank you very much for your help.

You're welcome.

 

The best way to confirm its using less power is to lock the fan speed and compare the GPU temps from stock to undervolt. If the temps go down while undervolted, then all is well.