K|NGP|N: Overvoltaging alone does not help ‘Maxwell’ to overclock

Orangey · 16 Jul 2015 at 11:05

Nvidia Corp.’s latest graphics processing units based on “Maxwell” architecture are rather good overclockers, but only to a certain degree. According to Vince “K|NGP|N” Lucido, a professional overclocker, without extreme methods of cooling (such as use of liquid nitrogen, chiller or other), most “Maxwell” GPUs just do not work at frequencies beyond certain limits even with ultra-high voltages, which is why in many cases it is useless to just amplify GPU voltage supply.

In a bid to overclock a microprocessor or a graphics processing unit, one needs to cool it down properly and increase voltage because operation at higher clock-rates requires additional power. Since higher power consumption means higher heat dissipation, requirements of better cooling increase with every additional 0.1V. Some previous-gen Nvidia GPUs could handle extreme temperatures and therefore could be overclocked to record frequencies even with air or water coolers. However, everything is different with “Maxwell”. The new graphics processing units from Nvidia require both additional voltage and exotic cooling methods to be overclocked to extreme frequencies.

What it means for end-users and makers of graphics adapters with fine coolers is that they will be unable to overclock “Maxwell” GPUs beyond certain points no matter what voltage they apply.

“With GeForce GTX 980 [GM204] and later GPUs, including GeForce GTX Titan X [GM200], the scaling on air/water has all but almost gone,” said Mr. Lucido in a forum post. “I would say about 95 per cent of all [Maxwell-based graphics cards] no matter [from] what [graphics card] brand, do not scale with more voltage than 1.25v-1.275v at temps warmer than 25°C or so. There is no magical BIOS that can effectively remove this.”

Very interesting, probably has something to do with density?

RavenXXX2 · 16 Jul 2015 at 11:12

So the likes of the 980 ti classified are a con.

Orangey · 16 Jul 2015 at 11:20

RavenXXX2 said:
So the likes of the 980 ti classified are a con.

Well, there's always liquid nitrogen...

andybird123 · 16 Jul 2015 at 11:32

RavenXXX2 said:
So the likes of the 980 ti classified are a con.

if you don't want to get in to changing the cooling or modding the bios to get higher tdp limits, then their value is questionable compared to cheaper alternatives, yes

however if you want to get a bit extreme with your overclocking efforts then they fulfil a niche in the market

for example, my msi gaming hits [email protected] but hits the tdp limit... I could, according to the above, go higher if I could get the voltage up to 1.25, which the card will do, but hitting the tdp limit makes it pointless, so bios mod is the only way to get more... so it depends if cards like the kingpin classified or 8pack HOF come with a higher tdp limit than the "normal" custom boards (Which are already up from 275W to 300W), 8pack made a comment the other day that he thinks the maximum Nvidia allow is 360W, which would still be a big chunk over the G1 etc.

if you unlock the tdp then cards like the kingpin might still hit higher with air/water than cards like the G1, MSI Gaming etc., but it is the law of diminishing returns

Ash0787 · 16 Jul 2015 at 11:35

I noticed this when overclocking the mini 970, that card seemed to be ultimately limited by power draw though as it only had one 4 pin plug.

So how long before people start using phase change on GPU or somehow using it instead of a watercooling radiator

LoadsaMoney · 16 Jul 2015 at 11:37

Overclockers Dream.

nashathedog · 16 Jul 2015 at 11:37

From what I remember regular Nvidia card voltage increases are limited to 1.2 and you need software like the Classified program to take it above that so all it means is you can't push it as far past the 1.2 limit as you could Kepler (presuming it hasn't changed since I had my 780 Classified) not that you can't increase it. So you can still improve your overclock some more by adding just .05 or .075 over the standard overvolt limit of 1.2.

Gregster · 16 Jul 2015 at 11:40

I thought this was standard knowledge?

nashathedog · 16 Jul 2015 at 11:43

Whoops

setter · 16 Jul 2015 at 11:43

Tbf, for 99% of users who are probably mainly overclocking for games or benchmarks like those on here. The 980ti cards clock plenty out of the box without much effort.

Yaayuh! · 16 Jul 2015 at 12:04

RavenXXX2 said:
So the likes of the 980 ti classified are a con.

Well, no

He's saying that overvolting doesn't gain you much if anything unless you're seriously cooling.

The classified is/should be for chilled water/LN2.

sieze2 · 16 Jul 2015 at 12:50

Rossi~ said:
Well, no

He's saying that overvolting doesn't gain you much if anything unless you're seriously cooling.

The classified is/should be for chilled water/LN2.

Except they said this part "What it means for end-users and makers of graphics adapters with fine coolers is that they will be unable to overclock “Maxwell” GPUs beyond certain points no matter what voltage they apply."

Gregster · 16 Jul 2015 at 12:54

It is the same with any GPU though. I added voltages to my 290X and if I added 100Mhz, I got negative returns compared to +50mV. The same with my 680 Lightnings and too much voltage ended in negative returns.

If you want to go big, go LN2 or Phase but for water and air, don't bother.

elmarko · 16 Jul 2015 at 13:00

The key is here really.

"1.25v-1.275" - for me, my cards run at significantly lower voltage (less than 1.9 @1500) - which then means I just hit the power limit.

To get a very nice high over-clock (beyond the standard) you need,

1. A decent chip.
2. Enough voltage room within the limits stated above.
3. Enough TDP (unlocked via BIOS modding)
4. Adequate cooling to prevent thermal voltage throttling.

On my two 980ti the issue with one is the power limit entirely (not too hot or too high on the volts) the second seems to require more volts to match the same but is also power limited.

setter · 16 Jul 2015 at 13:02

With the card in sig my limit without touching voltage is 1489mhz, +(160). Doesn't hit the power limit, 109 set in AB, graph shows 101 max in benchmarks. Could add volts but then that increases the chance of hitting the power limit, and the extra heat ups the temps so theres a chance of hitting that limit too. At 100% fan speed my max temp so far has been 60c. But some of these aftermarket cards will still downclock at 67c.

Gregster · 16 Jul 2015 at 13:03

Nvidia are very good at locking down the power limits

elmarko · 16 Jul 2015 at 13:06

What do you put on the memory, the higher I clock my memory the less stable my clocks are above 1450.

I can do 1550 on the core with -200 on memory, 1500 @ 0 & 1450 @ +500 (roughly) - the memory OC appears to be using more of the power available power, also 100% fans use a small percentage of total power availability also (compared to 80%).

I can clock higher @ 80% flat fan speed than 100%, easy to test as you monitor power usage - leave card in downclocked mode & just adjust the fan settings while the card idles.

If I recall correctly you can push usage up a few percent with the fan alone (another nice benefit from watercooling!)

Gregster said:
Nvidia are very good at locking down the power limits

I have no idea why the power limit is so restricted at default, while the +10% helps really it requires +20/30% from base to give it room to stretch it's legs.

They could keep the default the same, but open it up in the bios for changing within tools.

setter · 16 Jul 2015 at 13:07

200 on memory is the most I've tried so far.

Finners · 16 Jul 2015 at 13:08

What's the source of this? Got a friend waiting to buy a kingpin and I keep saying its not worth it.

Rroff · 16 Jul 2015 at 13:23

Gregster said:
I thought this was standard knowledge?

Was gonna post as I read the quote that this isn't exactly something new.

Some past nVidia GPUs if you could keep them sub 40C at all times you could get ridiculous overclocks without ever touching the voltage,