Increasing power limit without increasing clocks?

[RejZoR]

I was just wondering, does increasing the power limit without also increasing the clocks affect boost clock in any way? I mean If I push power limit further, GPU Boost should have more room to automatically pump up the clock right? But does it actually do that?

 

[Toothless]

Looks like it for my GPUs. I overclock a bit already with +50/200 but they do more like +100/300 on boosts.

 

[RejZoR]

The thing is, clocks monitoring is so weird with GTX 980. Almost every program shows different clocks. MSI Afterburner, GPU-Z and Unigine Valley. It seems like all these programs have serious problems reading out current actual clocks that are currently used because of GPU Boost.

 

[cadaveca]

The thing is, clocks monitoring is so weird with GTX 980. Almost every program shows different clocks. MSI Afterburner, GPU-Z and Unigine Valley. It seems like all these programs have serious problems reading out current actual clocks that are currently used because of GPU Boost.

valley is broken, use GPU-Z or EVGA precision. Afterburner is bloatware in my books. (yes, I know evga precision and afterburner are the same basic software).

increasing power limit will only increase clocks if your cards were throttling due to power usage already.

 

[RejZoR]

I thought GPU boost was clocking GPU higher for as long as power limit allowed it. So, increasing it should give it more space to work with, wouldn't it? I guess that's not the case...

 

[cadaveca]

I thought GPU boost was clocking GPU higher for as long as power limit allowed it. So, increasing it should give it more space to work with, wouldn't it? I guess that's not the case...

Yeah, not the case. Boost is a set MHz rating above "stock". It gets lowered if power usage or temps exceed their set points. Otherwise, they'd not be selling cards with different clocks, and there'd be no OC'ing, since it'd be automatic.

 

[RejZoR]

Is OVERBOOST function only available for EVGA graphic cards in EVGA Precision? Can't seem to enable it on my ASUS Strix no matter what...

 

[cadaveca]

Overboost is what?

Do you mean k-boost?

Totally not recommended for 24/7 use, hence why you cannot do it easily. but yes, precision should work.

 

[RejZoR]

No, I know Kboost just locks clocks at max, actually OVERBOOST. But it can't be selected, it's greyed out.

 

[cadaveca]

The point is taken, then? . Sorry, just my sense of humour.

 

[Vellinious]

Yes...the Maxwell GPUs do boost higher, if they can within the limitations of the voltage and power limits, without adding any offset to the core clock slider. My cards boost to 1429 and 1455 right out of the box, with the stock boost clock set to 1367.

 

[cadaveca]

That is normal. Actual boost clocks are about 70 MHz higher than listed boost clocks. My 980 does the same, but increasing the power limit ONLY increases clocks if the card was throttling... you screenshot show that you haven't actually increased the power limit.

likewise with my 708 TIs and my 780. I have 780 TI reference, listed boost clock for my card is 928, but actual boost clock is 1020.

 

[RejZoR]

I was asking this because this documentation is giving a different impression:
http://www.geforce.com/hardware/technology/gpu-boost-2/technology

 

[W1zzard]

I was just wondering, does increasing the power limit without also increasing the clocks affect boost clock in any way? I mean If I push power limit further, GPU Boost should have more room to automatically pump up the clock right? But does it actually do that?

that is correct, but only in case your card runs into the power limit in games (not thermal limit, not max boost, not boost capped by voltage)

 

[RejZoR]

Meaning if you push too high voltage that you don't actually need, you'll hit the power limit faster, meaning lower voltage could actually be more beneficial if it's stable of course. Hm.

 

[W1zzard]

Meaning if you push too high voltage that you don't actually need, you'll hit the power limit faster, meaning lower voltage could actually be more beneficial if it's stable of course. Hm.

(what you say is true), but I mean with everything at stock. Boost also increases voltage, but there is a fixed limit beyond which voltage will not be increased.

http://www.techpowerup.com/reviews/NVIDIA/GeForce_GTX_980_Ti/35.html

End of the page

 

[the54thvoid]

Meaning if you push too high voltage that you don't actually need, you'll hit the power limit faster, meaning lower voltage could actually be more beneficial if it's stable of course. Hm.

Yes, lower voltage for higher clocks is what the silicon lottery is all about for mainstream overclockers.
My own card works better so far at 1.18-1.19v at 1550mhz than it does trying to run at 1.2v. I need cooler temps on Maxwell to run higher volts (under 50 degrees is good for the above but for higher clocks I need ambient temps).

 

[trog100]

my two 970 cards seem to throttle down even with the power limit set to 110 in afterburner.. the hotter one of the two shows around 1240mhz the other one around 1300mhz..

the temps are around 71c and 76c.. with the power limit set to normal i lose around 100mhz from each card..

my cooling is good and i am using furmark to load the cards and read the figures.. something wants to keep the temps in the low seventies..

the bottom line is unless i up that power limit my cards clock down more.. i am running them at stock voltage.. the card temps stay the same but they definitely throttle down to keep the temps well below 80c..

it kind of seems that without better cooling whatever you do wont make them go any faster.. they simply throttle down to maintain what i consider a rather low temp low well below 80c..

my cards are evga and i have two large side fans feeding room temp air directly to them.. if i block the side case fans off they throttle down even more and the card temps stay the same..

the card fans on auto never run flat out.. the cards throttle down rather than cranking the fans up.. maybe manually increasing the card fan speeds would allow them to run quicker that is not something i have tried yet.. having said that if they run faster i may have to slow them down to maintain stabiilty.. he he

trog

ps.. i just altered the fan profile to run flat out at 80c.. the noise is horrendous and the card temps dropped to around 50c.. my speeds never altered though so its back to the auto profile.. he he

 

[Vayra86]

Yeah, not the case. Boost is a set MHz rating above "stock". It gets lowered if power usage or temps exceed their set points. Otherwise, they'd not be selling cards with different clocks, and there'd be no OC'ing, since it'd be automatic.

This is true, but not the whole truth. (Yeah, that's DEEP!)

If you push Power Limit to max and manually push core clocks, you can still see boost clock doing some work.
1. it will limit the clocks whenever it hits the temp limit or comes close to it (pretty advanced detection here, it generally clocks back just right to get temps in check)
2. it will push beyond your max core clocks with the same boost bins as it had before your OC, if there is power/temperature headroom

Therefore analyzing boost clock behaviour is a very good tool to see quickly if your OC is actually making sense. If it is not using all the original boost bins, you might as well dial back the core clock OC. In a sense, this makes the boost clocks a very efficient OC stability tool, because they are a warning sign that you are approaching your GPU's limits in power delivery/achievable core clock.

Controlling boost clocks through just the temperature slider is generally a bad idea because it will increase the aggressiveness of the temperature limiting through boost clocks. If your airflow is right, any card should be fine with a very loose temp setting because the driver will limit the card in any case. If you have temperature issues, the best way to solve them is to adjust the fan profile to keep a card within 'boostable' temps.

To chime in on trog100: the reason stock power settings limit boost clocks in some games while they do not in others, is because core clock is not the whole story of GPU utilization. Some games will use more of the GPU internals than others. Tesselation is a good example of this - generally games that use a lot of tesselation will cause a hotter GPU while showing similar utilization on the OSD. If you test overclocks; use precisely these games to really test your OC. This is also a reason the Valley, and in a greater sense the Heaven bench are very good for stability testing of OCs (and yes, their GPU clock readings are off by a large margin).

Last, boost clocks do not affect memory at all, contrary to what Toothless assumed.

 

[Vellinious]

^^This.....

 

[Vellinious]

(what you say is true), but I mean with everything at stock. Boost also increases voltage, but there is a fixed limit beyond which voltage will not be increased.

http://www.techpowerup.com/reviews/NVIDIA/GeForce_GTX_980_Ti/35.html

End of the page

Easy fix for that...mod the bios.

 

[RejZoR]

I've also noticed that my GTX 980 will lockup and crash the driver in Unigine Valley when running at 4K with +200MHz on GPU and +75MHz on VRAM (with 125% limit). But only if I leave fans at stock. If I change the fan curve, it'll work happily even though it doesn't even reach the thermal limit of it. But it'll be significantly louder. Seems like it's quite sensitive where HD7950 that I had you could hammer at temperatures of 85°C and it would still run without any problems.

 

[Vellinious]

The cooler you keep Maxwell, the better, faster and more stable they'll run.