How is Boost 2.0 better than Boost 1.0?

[Jacez]

I've been reading around and I'm still confused about this.

The GTX 770 is based on the same GK104 core as the GTX 680 and it's overclocked, but it takes less power and runs cooler..

W1zz says that this is because of Boost 2.0, but I'm having a hard time understanding how that works. Can anyone explain?

 

[m1dg3t]

Short answer: Because it's (the algorithim) more efficient.

 

[W1zzard]

http://www.techpowerup.com/reviews/NVIDIA/GeForce_GTX_Titan/30.html

 

[m1dg3t]

http://www.techpowerup.com/reviews/NVIDIA/GeForce_GTX_Titan/30.html

This what makes full card waterblocks so good these days

 

[Sasqui]

This what makes full card waterblocks so good these days

Yea, it's basically thermal throttling on steroids. Awesome article, W1zz... I got it first read. At least I think I did.

 

[Flibolito]

This what makes full card waterblocks so good these days

Couldn't agree more.

 

[Jacez]

http://www.techpowerup.com/reviews/NVIDIA/GeForce_GTX_Titan/30.html

With GPU Boost 2.0, temperature is also taken into account

So, let me see if I have this right..

Boost 1.0 looked at the card's power draw and if it was under specification, it allowed for a higher clock speed.

Boost 2.0 looks at the card's temperature and if it's under 80C, allows a higher clock speed, and if it's over 95C it goes back to 2D clocks.


But the GTX 770 never reached 80C, so that would mean that Boost 2.0 would overclock it to the absolute max, and it still didn't reach 80C.

Where as, the GTX 680 was being pushed equally hard (as its clock speed was not higher), and yet it reached 85C..


Am I missing something? This doesn't make any sense..

 

[blibba]

Am I missing something?

Yes. Going "back to 2D clocks at 95 degrees" would be thermal throttling, which uses the same mechanisms, but is about protecting the card from damage, not picking the optimal clock speed.

Simplified somewhat, it's like this:

Boost 1.0 algorithm: Select the lowest of the following:

• Maximum boost clock
• Maximum clock that can be achieved without exceeding TDP limit

Boost 2.0 algorithm: Select the lowest of the following:

• Maximum boost clock
• Maximum clock that can be achieved without exceeding TDP limit
• Maximum clock that can be achieved without exceeding temperature limit

Often it is the temperature constraint that binds, which is why you tend to see reported temperatures of almost exactly 80 degrees - this is the default temperature limit. A simple way to improve performance in this case is to turn up fan speeds - then a higher clock speed can be achieved without passing 80 degrees. Or, equivalently, you can leave fan speeds where they are but increase the temperature limit.

The main reason Boost 2.0 is better is that it allows for a less conservative TDP limit, because they don't have to worry about temperatures when they set that.

 

[Jacez]

Often it is the temperature constraint that binds, which is why you tend to see reported temperatures of almost exactly 80 degrees - this is the default temperature limit. A simple way to improve performance in this case is to turn up fan speeds - then a higher clock speed can be achieved without passing 80 degrees. Or, equivalently, you can leave fan speeds where they are but increase the temperature limit.

The main reason Boost 2.0 is better is that it allows for a less conservative TDP limit, because they don't have to worry about temperatures when they set that.

So, you're saying that with the GTX 680, they had to rely on Boost 1.0, which does not take temperatures into account, so they limited the TDP.

With the GTX 770, they now rely on Boost 2.0, which does take temperatures into account, making the overclocking safer and more precise, so they raised the TDP restriction.

This would explain why the card is faster, but it does not explain why, even at a higher TPD, it takes less power, run cooler and as I've just found out - far less noisy.

 

[blibba]

it takes less power

Most reviews show it taking slightly more power, but in any case, some binning may be at work - 28nm is now more mature, so the yields ought to be improved vs. when the GTX680 originally launched, allowing lower default voltages at any given clock speed.

run cooler and as I've just found out - far less noisy.

It has a better stock cooler.

 

[Jacez]

Most reviews show it taking slightly more power, but in any case, some binning may be at work - 28nm is now more mature, so the yields ought to be improved vs. when the GTX680 originally launched, allowing lower default voltages at any given clock speed.



It has a better stock cooler.

So, now you're saying that binning and a better cooler are the answers to my questions.. and not Boost 2.0, like W1zz said?

 

[blibba]

So, now you're saying that binning and a better cooler are the answers to my questions.. and not Boost 2.0, like W1zz said?

These things are all inter-related, and truly I don't think anyone outside of Nvidia could give you a concrete answer to your various questions. But I stand by everything I've said, and I don't think it's necessarily incompatible with what Wizz has said.

 

[TheoneandonlyMrK]

So, now you're saying that binning and a better cooler are the answers to my questions.. and not Boost 2.0, like W1zz said?

As time goes on they get better at producing chips and validation/binning plus they sometimes make slight optimisations to the chips finer points called steppings plus boost 2 has more p states (oc and std clock and volts levels) so the card and driver's run it as fast as temps and tdp allow within it's limits (set by nvidia to limit Rmas), my take on it.

 

[Jacez]

These things are all inter-related, and truly I don't think anyone outside of Nvidia could give you a concrete answer to your various questions. But I stand by everything I've said, and I don't think it's necessarily incompatible with what Wizz has said.

W1zz said that Boost 2.0 was the only reason for the disparity.

But what I've found is that W1zz's review is off (the card takes more power, not less), and the cooler on the GTX 770 is more efficient (vapor chamber vs. heatpipes).

So, I really don't see how Boost 2.0 has anything to do with this.

 

[W1zzard]

W1zz said that Boost 2.0 was the only reason for the disparity.

But what I've found is that W1zz's review is off (the card takes more power, not less), and the cooler on the GTX 770 is more efficient (vapor chamber vs. heatpipes).

So, I really don't see how Boost 2.0 has anything to do with this.

i didn't say that. yes, the card is clocked higher than gtx 680, but boost 2.0 helps get more performance at same clock.

power consumption is lower than gtx 680. are you by any chance looking at reviews that measure full system power consumption?

 

[Jacez]

i didn't say that. yes, the card is clocked higher than gtx 680, but boost 2.0 helps get more performance at same clock.

power consumption is lower than gtx 680. are you by any chance looking at reviews that measure full system power consumption?

When I asked you why the GTX 770 was cooler and takes less power your response was "Boost 2.0 algorithm." That was it.

I started a thread on [H] and apparently, most reviewers are saying that the GTX 770 takes a bit more power, not less. They're saying that something is wrong with your review.

But I trust your reviews the most, which is why I'm confused.