How much is power consumption increased when a GPU is overclocked?

[Alexlomm]

I want to get an idea of how to choose proper wattage PSUs with possible GPU overclocking in mind.

Say a 550w PSU is enough for a GTX 970 running at stock settings. How much would the wattage increase in case of overclocking the GPU to the max? Would the changes in card's power consumption be negligible, or would it be increased as much as 2x or 3x of the original demand, thus arising the need for stronger PSU?

 

[morpheas768]

Well, definitely not 2x or 3x.
But really, there are too many factors here:
- Which gfx card are we talking about? (be specific, not just the GPU. 970 Strix by Asus? - Example)
- What sort of overclocking are you looking for? (There are mild 2-8% oc, and there are 20% oc on the gpu core)
- The rest of your build matters quite a bit. You might have a low power i5, or an i3, only 1 SSD, and 1 HDD (you get the idea)
- The PSU also matters. Not all 550W PSU's are the same. Some are very high quality, delivering up to 548W nominal power on the 12V rail, and some cant even deliver 550W continuous power, but rather Peak power, which means they arent really 550W units.
- Also, the application you are running matters. Apps like Furmark put extreme load on the card, stress it to its limits, causing it often even surpass the specified TDP by Nvidia/Amd. But an average game will not cause the card to reach its TDP, usually will be below that.

Would need a lot more information here. But as a general rule, no matter what you do, I dont think you can double a GTX 970's TDP.

 

[Alexlomm]

Well, definitely not 2x or 3x.
But really, there are too many factors here:
- Which gfx card are we talking about? (be specific, not just the GPU. 970 Strix by Asus? - Example)
- What sort of overclocking are you looking for? (There are mild 2-8% oc, and there are 20% oc on the gpu core)
- The rest of your build matters quite a bit. You might have a low power i5, or an i3, only 1 SSD, and 1 HDD (you get the idea)
- The PSU also matters. Not all 550W PSU's are the same. Some are very high quality, delivering up to 548W nominal power on the 12V rail, and some cant even deliver 550W continuous power, but rather Peak power, which means they arent really 550W units.
- Also, the application you are running matters. Apps like Furmark put extreme load on the card, stress it to its limits, causing it often even surpass the specified TDP by Nvidia/Amd. But an average game will not cause the card to reach its TDP, usually will be below that.

Would need a lot more information here. But as a general rule, no matter what you do, I dont think you can double a GTX 970's TDP.

Thanks for an answer. Consider just a GTX 970. About how much would it's power consumption increase, had we OCed it to the max?

 

[morpheas768]

Read this: http://www.anandtech.com/show/8568/the-geforce-gtx-970-review-feat-evga/16
Its a review of the EVGA GTX 970 FTW. They only did a mild OC (since the FTW version already has high clocks by EVGA), and that resulted in an extra ~9-15W in Crysis 3 and Furmark.

Now read this: http://www.overclockers.com/gigabyte-gtx-970-extreme-video-card-review/
A review of the GTX 970 Extreme by Gigabyte.
Their OC is moderate (76MHZ) considering the cards already high stock clocks by Gigabyte.
It resulted in ~22 Watts more power consumed during 3D Mark Firestrike and Unigine Valley benchmarks.

The GTX 970 is known for its low power consumption and low temperatures. However, some offerings by certain partners consume more power than others, and some consume less. Typically, the reference boards tend to be more conservative, but not always.
For example, Gigabyte's Extreme and G1 Gaming tend to consume more than reference boards, and the same can be said about the MSI Gaming. This doesnt mean higher temps though, they are actually quite cool, and overclock really well.

Which GTX 970 have you got? It matters a bit.

Anyway, the increase in power consumption should only be a problem if you're kinda on the limit of what your PSU can provide for your system.

If you're asking me to give you just a number off the top of my head, I'd say about 25% increase on the card's TDP with a really high overclock profile and a card that is on reference clocks. And no, you cant take that number to the bank, because again, it really matters if you're going to run Crysis 3, Furmark, or just a little Minecraft and League of Legends.

From the reviews I've read, the Asus GTX 970 Strix seems to consume the least power, and overclocks well, all things considered.

 

[Alexlomm]

Which GTX 970 have you got? It matters a bit.

Anyway, the increase in power consumption should only be a problem if you're kinda on the limit of what your PSU can provide for your system.

If you're asking me to give you just a number off the top of my head, I'd say about 25% increase on the card's TDP with a really high overclock profile and a card that is on reference clocks. And no, you cant take that number to the bank, because again, it really matters if you're going to run Crysis 3, Furmark, or just a little Minecraft and League of Legends.

I haven't got any GPU yet, just wanted to get an overall idea of how does overclocking affect power consumption of the card. Thanks for the great answer, this information is exactly what I was looking for!

 

[morpheas768]

I haven't got any GPU yet, just wanted to get an overall idea of how does overclocking affect power consumption of the card. Thanks for the great answer, this information is exactly what I was looking for!

You're welcome.
But you might want to consider a GTX 1070, since its a lot faster than 970, and even though prices are high and availability is low atm, these problems will be corrected soon.
Also, the 1070's power consumption is only a tiny bit higher than 970's, making the stock non-oc 1070 a far better value.

 

[Alexlomm]

I haven't got any GPU yet, just wanted to get an overall idea of how does overclocking affect power consumption of the card. Thanks for the great answer, this information is exactly what I was looking for!

You're welcome.
But you might want to consider a GTX 1070, since its a lot faster than 970, and even though prices are high and availability is low atm, these problems will be corrected soon.
Also, the 1070's power consumption is only a tiny bit higher than 970's, making the stock non-oc 1070 a far better value.

Actually I'm leaning towards RX 480 since it's cheaper and is just right for 1080p IMHO. Thanks for the advice, though.

 

[morpheas768]

Actually I'm leaning towards RX 480 since it's cheaper and is just right for 1080p IMHO. Thanks for the advice, though.

Yes, that is also a good choice. I only suggested the 1070 because it is in the same category and price range as the GTX 970 used to be, and I am hesitant to recommend purchasing a 970 at this point in time.