Allow undervolting the CPU.

[SpiraTech]

I was just looking at how some people have been able to undervolt their Steam Deck using third party tools (which no longer work after a recent update). As with many AMD desktop processor users I have undervolted my CPU and it has had massive gains and much lower power consumption and temperatures whilst also increasing performance. Of course, not all CPUs are able to do this, there are an odd few that can't but it'd be nice to have the option.

Just my suggestion that Valve should allow this as an additional option - perhaps under an advance setting for "power users".

Thanks

[ReBoot]

There already is a power-limiting option for the CPU. Have you tested if it works your use case as well?

[SpiraTech]

Originally posted by ReBoot:

There already is a power-limiting option for the CPU. Have you tested if it works your use case as well?

Thanks - yeah that can be handy sometimes and I do use it a lot, but undervolting is a little different as it would also allow for higher performance / lower temps at the same watts (power limit).

[ReBoot]

Have you tried the results it yields? The whole idea with getting more power by feeding the CPU less power works, sure, but isn't exactly an exact science. My point is, just because it's a different thing under the hood, have you tested whether those two things yield comparable results?

Analogy: a chemical car & an electrical car look VASTLY different under the hood, yet they serve the same purpose: getting from A to B without public transportation.

[SpiraTech]

Originally posted by ReBoot:

Have you tried the results it yields? The whole idea with getting more power by feeding the CPU less power works, sure, but isn't exactly an exact science. My point is, just because it's a different thing under the hood, have you tested whether those two things yield comparable results?

Analogy: a chemical car & an electrical car look VASTLY different under the hood, yet they serve the same purpose: getting from A to B without public transportation.

Well, it's already widely tested and researched around the world so no point reinventing the wheel. Power limits =/ core voltage offsets

Besides, I cannot test it anyway as I mentioned the latest BIOS currently prevents this. I'd be happy to share with you otherwise. There are also various posts / videos online showing what you could do with undervolting the Steam Deck.

[ReBoot]

Originally posted by Technex:

Power limits =/ core voltage offsets

Yeah, I got that far. My point is, two unequal things can still produce rather equal results and since results are what ultimately counts, that's the more interesting question than whether 2 obviously-not-the-same-things are equal.

[shadowboy813]

Originally posted by Technex:

Originally posted by ReBoot:

There already is a power-limiting option for the CPU. Have you tested if it works your use case as well?

Thanks - yeah that can be handy sometimes and I do use it a lot, but undervolting is a little different as it would also allow for higher performance / lower temps at the same watts (power limit).

Power consumption is directly related to voltage. Cutting the power by 75% is the same as undervolting by 50% (P = V^2 / R, I suggest you look up Ohm's law). The APU at 3.75W is undervolted by half.

[SpiraTech]

Originally posted by shadowboy813:

Originally posted by Technex:

Thanks - yeah that can be handy sometimes and I do use it a lot, but undervolting is a little different as it would also allow for higher performance / lower temps at the same watts (power limit).

Power consumption is directly related to voltage. Cutting the power by 75% is the same as undervolting by 50% (P = V^2 / R, I suggest you look up Ohm's law). The APU at 3.75W is undervolted by half.

That is true, but you are forgetting about voltage vs performance (clock speed + curves).

I suggest you look at AMD PBO2 and negative voltage offset curves.

CPU performance is a little more complex than simple electronics.

A voltage offset is not the same as the curve offsets, additionally what happens if I want to go lower than the lowest limit set currently? This is where an additional voltage drop could help.

Besides, again you are missing the point, I am asking about undervolting, not power limits, they are a very different thing.

Please don't bother commenting unless you understand how CPUs work.

[GIBbeer]

That's the only thing now which put my Steam Deck purchase decision on hold. I keep my fingers crossed for the unlocking the UV in next BIOS update.

[Prezidentas]

Originally posted by GIBbeer:

That's the only thing now which put my Steam Deck purchase decision on hold. I keep my fingers crossed for the unlocking the UV in next BIOS update.

It's not gonna turn the Steam Deck into a powerful gaming PC anyways.

[GIBbeer]

Originally posted by Škoda 14Tr:

Originally posted by GIBbeer:

That's the only thing now which put my Steam Deck purchase decision on hold. I keep my fingers crossed for the unlocking the UV in next BIOS update.

It's not gonna turn the Steam Deck into a powerful gaming PC anyways.

Sure, that's obvious, but along with other improvements it can perform better than now...