CPU Researching 'performance-per-watt' and power efficiency? (Undervolting, etc.)

Zeroth Alpha

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Jul 24, 2016
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You can find it in the images above. The X-axis is voltage and Y-axis is frequency. GPU-boost will pick the lowest voltage for the same frequency, so you want to the curve to flatten after your intended point. You can click L to lock it to a specific voltage and frequency combination. The images are of my gaming profile. Runs a little higher at 1700mhz instead.
 
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Biowarejak

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I DIDN'T KNOW THAT WAS A BUTTON!

Okay, time to go check that out.

-EDIT-

Huh, mine doesn't have that option.
 
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Biowarejak

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They are. I'm using a Maxwell-era GPU though, maybe that's the issue?
 

Zeroth Alpha

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Jul 24, 2016
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Only available on the newest cards. With Maxwell & Kepler increasing the GPU clock while lowering power limit results in lower voltage.
Yeah, this is only with GPU Boost 3.0, which for now is pascal only.

Edit:
Also, you could use a bios tweaker to gain absolute mastery over your card if you can stomach the risks. I did it for my GTX 780, and was kinda sad that pascal has no such utility. Would love to enable fanless idle...
 
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Biowarejak

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Hopefully won't be an issue much longer :) seems like a pretty nifty feature.
 

Raxe

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Mar 3, 2017
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You can find it in the images above. The X-axis is voltage and Y-axis is frequency. GPU-boost will pick the lowest voltage for the same frequency, so you want to the curve to flatten after your intended point. You can click L to lock it to a specific voltage and frequency combination. The images are of my gaming profile. Runs a little higher at 1700mhz instead.


I managed around 1.8ghz and +300mhz at 0.85v, pretty substantial drop on wattage consumption! Around 55-60watts when it was 110-120w at full oc (+210 core + 500 mem 1.062v)

The only drawback is the idle. It´s the same as overclock your cpu in the bios with the fixed voltage, it will stay at full velocity even on idle, the same goes here... It´s a great way to deal with power consumption when you´re gonna use the gpu in complex calculations/renders or some games but needed to be disabled if no

With my GTX 1060, idle consumption marks 30watts roughly with Hwinfo.
 
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Chrizz

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Jan 23, 2017
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I did a lot of testing today overclocking and underclocking my gtx 970. I have an rvz01, so thermals are quite a big problem. I can get 1480 MHz boost and +350 MHz on the memory at stock voltages and 87% fanspeed at 84°C. However, when I limit the fanspeed to 54%, I'm still able to get 1202 MHz (which is still above the core clock) and +350 MHz on the memory, this is also at 84°C. (here is the fan 'curve')
The reduced clockspeed may seem pretty bad (±20%), however, the performance decrease was only about 12%, meanwhile, the noise went from unbearable even with headphones on to very acceptable.
I don't know how to decrease voltages on my GPU, MSI afterburner only allows me to increase it, but even without undervolting, I managed to significantly improve my gaming experience.
(BTW, both test configurations where at 85% power limit.)

I guess overclocking in an itx system really doesn't make a ton of sense; you need so much better cooling to squeeze out a small amount of performance. (And I didn't even increase the voltage, doing so probably yields even smaller diminishing returns.)
 
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zovc

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I don't know how to decrease voltages on my GPU, MSI afterburner only allows me to increase it, but even without undervolting, I managed to significantly improve my gaming experience.

Have you made sure you've enabled voltage settings in Afterburner's settings?

@Zeroth Alpha has pictures of it here.
 
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Chrizz

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Jan 23, 2017
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Have you made sure you've enabled voltage settings in Afterburner's settings?

@Zeroth Alpha has pictures of it here.

I have, but this is currently only available for pascal cards. For me the slider starts at 0:
 
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Thehack

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I did a lot of testing today overclocking and underclocking my gtx 970. I have an rvz01, so thermals are quite a big problem. I can get 1480 MHz boost and +350 MHz on the memory at stock voltages and 87% fanspeed at 84°C. However, when I limit the fanspeed to 54%, I'm still able to get 1202 MHz (which is still above the core clock) and +350 MHz on the memory, this is also at 84°C. (here is the fan 'curve')
The reduced clockspeed may seem pretty bad (±20%), however, the performance decrease was only about 12%, meanwhile, the noise went from unbearable even with headphones on to very acceptable.
I don't know how to decrease voltages on my GPU, MSI afterburner only allows me to increase it, but even without undervolting, I managed to significantly improve my gaming experience.
(BTW, both test configurations where at 85% power limit.)

I guess overclocking in an itx system really doesn't make a ton of sense; you need so much better cooling to squeeze out a small amount of performance. (And I didn't even increase the voltage, doing so probably yields even smaller diminishing returns.)

The RVZ01 has pretty good cooling for the GPU. Make sure you feed it with two 120mm fans and keep the case standing.
 

Biowarejak

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With the tools mentioned though, it could be feasible to use a lower-wattage PSU and avoid redlining it the whole time. I wouldn't recommend it, but you could.
You, in this case, being the all-inclusive term :)
 

Zeroth Alpha

Cable Smoosher
Jul 24, 2016
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I managed around 1.8ghz and +300mhz at 0.85v, pretty substantial drop on wattage consumption! Around 55-60watts when it was 110-120w at full oc (+210 core + 500 mem 1.062v)

The only drawback is the idle. It´s the same as overclock your cpu in the bios with the fixed voltage, it will stay at full velocity even on idle, the same goes here... It´s a great way to deal with power consumption when you´re gonna use the gpu in complex calculations/renders or some games but needed to be disabled if no

With my GTX 1060, idle consumption marks 30watts roughly with Hwinfo.
Sorry, I think I was a little unclear about this. You can click L to lock it to a specific frequency-voltage combination while you're testing what works well for your card. Then you can disable the lock when you're done. As long as your intended peak combination, in your case +300mhz at 0.85v, is the highest frequency over every subsequent voltage point, it will clock down and up along the curve from idle to that point. At least, that's what I found with my testing. I currently lock it because I'm always running primegrid.
 
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Zeroth Alpha

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Jul 24, 2016
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I have, but this is currently only available for pascal cards. For me the slider starts at 0:
Yeah, the only real option is to use this utility (which actually gives even finer grain control but has an actual chance of bricking your card). If anyone does want to attempt this, I'd recommend a great deal of care and a whole lot of risk tolerance. It is a lot safer if you have a dual bios card though.
https://www.techpowerup.com/download/maxwell-ii-bios-tweaker/
 
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