Why does undervolting improve performance?

[HARDWELL9191]

I'm a newbie at this undervolting stuff. So just wondering shouldn't less voltage decrase the power of the cpu and not increase It. I've tried undervolting and had better performance. How exactly is this possible? How does this all work?

[podkall]

Doesn't always work like that, but

 

GPU that becomes unstable at higher voltage, is simply more stable at (underclocked) lower voltage.

[Deadpool2onBlu-Ray]

2 minutes ago, HARDWELL9191 said:

I'm a newbie at this undervolting stuff. So just wondering shouldn't less voltage decrase the power of the cpu and not increase It. I've tried undervolting and had better performance. How exactly is this possible? How does this all work?

Because of thermal headroom

[HARDWELL9191]

1 minute ago, ShawtyT30beTHICCC said:

Because of thermal headroom

Would appreciate If you could explain a bit more yeah I get that this drops the temps and therefore the performance gets better. But I don't get It I just decreased the voltage to the CPU shouldn't the performance also drop with the temps?

[BobVonBob]

Undervolting generally only increases performance in two related circumstances, either the chip is power limited (usually only a thing in laptops/small integrated devices) or it's thermal limited. The reason undervolting can increase performance in those cases is because reducing the voltage, and thus the power draw of the chip, can help prevent the chip from hitting those limits.

[HARDWELL9191]

3 minutes ago, BobVonBob said:

Undervolting generally only increases performance in two related circumstances, either the chip is power limited (generally only a thing in laptops/small integrated devices) or it's thermal limited. The reason undervolting can increase performance in those cases is because reducing the voltage, and thus the power draw of the chip, can help prevent the chip from hitting those limits.

So basically my cooler is the problem and therefore the cpu is throttling and that's why I get better performance with undervolting?

[podkall]

1 minute ago, HARDWELL9191 said:

So basically my cooler is the problem and is throttling the cpu and that's why I get better performance with undervolting?

Not necessairly cooler problem.

[Bad5ector]

2 minutes ago, HARDWELL9191 said:

But I don't get It I just decreased the voltage to the CPU shouldn't the performance also drop with the temps?

Think of it as a reverse overclock, you're trying to get your CPU to run as fast as possible at the lowest possible voltage without crashing. Instead of trying to increase the voltage and the CPU clock speed. Undervolting you are telling the CPU to try and run at whatever setting it is with limited voltage. This will produce less heat and less heat means it can run at the higher speeds longer. If you get a really good chip, you could undervolt and even OC a bit. Get the highest clock possible, at the lowest voltage possible is the name of the game.

[YoungBlade]

2 minutes ago, HARDWELL9191 said:

So basically my cooler is the problem and therefore the cpu is throttling and that's why I get better performance with undervolting?

I would assume from your other posts that your CPU is a Ryzen CPU. Ryzen's boosting behavior is rather complex, and has multiple factors to it - temperature and power being the most important.

 

For Ryzen 3000 and 5000 series, the CPUs do a light throttling before a heavy thermal throttling at TJmax. Keeping a Ryzen CPU cool will allow it to boost higher. This is how Precision Boost works - which is not to be confused with Precision Boost Overdrive (PBO). Also, undervolting Ryzen will allow the CPU to remain under its power budget more easily, which will let the CPU boost higher if it would otherwise encounter the PPT limit.

[HARDWELL9191]

3 minutes ago, Bad5ector said:

Think of it as a reverse overclock, you're trying to get your CPU to run as fast as possible at the lowest possible voltage without crashing. Instead of trying to increase the voltage and the CPU clock speed. Undervolting you are telling the CPU to try and run at whatever setting it is with limited voltage. This will produce less heat and less heat means it can run at the higher speeds longer. If you get a really good chip, you could undervolt and even OC a bit. Get the highest clock possible, at the lowest voltage possible is the name of the game.

If I had a good AIO for example I wouldn't even need to undervolt then cuz It could keep the CPU at max boost clocks pretty much all the time since It wouldn't be thermally limited right?

[YoungBlade]

Just now, HARDWELL9191 said:

If I had a good AIO for example I wouldn't even need to undervolt then cuz It could keep the CPU at max boost clocks pretty much all the time right?

Maybe, but only in thermally constrained situations. If it's a power limit problem, then the AIO wouldn't help. And since you have a 5800X3D (I believe) you can't raise the PPT, TDC, or EDC limits with PBO, and therefore undervolting is the only way to (in a sense) give the CPU more of a power budget.

[Bad5ector]

1 minute ago, HARDWELL9191 said:

If I had a good AIO for example I wouldn't even need to undervolt then cuz It could keep the CPU at max boost clocks pretty much all the time right?

Well, not really. Still will hit higher temps regardless stock than you would undervolting.

[Heliian]

Undervolting is not the magical solution that some claim, I have yet to see any quantifiable data on the subject.  

 

Lowering the power will reduce temps but performance will vary. 

[freeagent]

Max boost will not happen under stock power settings on zen 3, neither will max performance. If you are having thermal issues within the stock limits you need to work on your cooling. 

[HARDWELL9191]

5 minutes ago, Bad5ector said:

Well, not really. Still will hit higher temps regardless stock than you would undervolting.

 

6 minutes ago, YoungBlade said:

Maybe, but only in thermally constrained situations. If it's a power limit problem, then the AIO wouldn't help. And since you have a 5800X3D (I believe) you can't raise the PPT, TDC, or EDC limits with PBO, and therefore undervolting is the only way to (in a sense) give the CPU more of a power budget.

 

10 minutes ago, Bad5ector said:

Think of it as a reverse overclock, you're trying to get your CPU to run as fast as possible at the lowest possible voltage without crashing. Instead of trying to increase the voltage and the CPU clock speed. Undervolting you are telling the CPU to try and run at whatever setting it is with limited voltage. This will produce less heat and less heat means it can run at the higher speeds longer. If you get a really good chip, you could undervolt and even OC a bit. Get the highest clock possible, at the lowest voltage possible is the name of the game.

 

16 minutes ago, BobVonBob said:

Undervolting generally only increases performance in two related circumstances, either the chip is power limited (usually only a thing in laptops/small integrated devices) or it's thermal limited. The reason undervolting can increase performance in those cases is because reducing the voltage, and thus the power draw of the chip, can help prevent the chip from hitting those limits.

Thank you all for the help.

[IkeaGnome]

Timestamped the video. Less voltage makes less heat. You can go past the point of gaining performance and actually lose it, but the video does a really good job at simplifying it.