Should I Undervolt the Ryzen 9 7940HS?

Per the topic, I’m thinking about trying to undervolt the CPU. Since this is an AMD Advantage though, would that even be necessary? I could absolutely imagine that since Framework and AMD are working so closely together on this product, that a great stock voltage has already been selected. What do you think?

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honestly you could lean either way. i’d expect the stock voltages to be more conservative to maximize stability, so you could maybe shove it down a bit. it’d be a fun experiment, but i doubt it’d do much. i’d love to be proven wrong, though

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From my experience, undervolting has had massive benefits (5000 series).
Additionally, modern CPUs run too high up on the Freq.-Voltage graph imo, so underclocking even 10% can sometimes drop peak power usage by 30-50%. May be worth considering.

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I don’t know how robust the controls in the Framework 16 BIOS will be, but I have used the Ryzen Master software for my desktop and had good results with it. If you don’t want to jump straight into fine tuning then the eco mode option is a good starting place if you don’t mind losing a bit of performance for a large savings in power consumption and heat.

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Would be interesting to see the impact on battery usage.
I may give it a try when my FW16 unit arrives (Batch 1). As my workstation still works, I think the first weeks/months will be dedicated to testing the sh*t out of it :slight_smile: Just because I can :smiley:

Afaik you can’t do that, unless the mainboard supports it, but please do give it a try.
Framework hasn’t officially announced if it’s supported, so we won’t know unless you give it a try.

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If it turns out to actually be possible, you probably should.

As it is now it looks like amd locked that out a generation ago and intel a bit before that.

It’s not been confirmed the Framework supports that feature.

Has anyone supported that feature on a 6th or 7th gen amd mobile processor?

The 7940HS is listed as supporting Curve Optimizer Voltage Offsets so it should be possible in theory. The 7840HS does not support it unfortunately.

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Has anyone been able to undervolt a 7940hs on any device jet? Even if the device manufacturer does not support it, it should be accessible vie smokeless umaf if the registers for it actually exist.

Apparently someone did:

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Not sure if I am more glad it still works or mad about it being locked down on other versions of the same chip.

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ShiroudanRegular

1d

From my experience, undervolting has had massive benefits (5000 series).
Additionally, modern CPUs run too high up on the Freq.-Voltage graph imo, so underclocking even 10% can sometimes drop peak power usage by 30-50%. May be worth considering.

Adding to this.

The equation for power consumption is: Power = Capacitance * Frequency * Voltage^2

Also, dropping voltage drops max frequency (although you may have to manually configure this). Capacitance is part of the hardware design, you can’t do anything about that. I’m going to look into this once I get my order. Longer battery life is more important that power. The Ryzen 7s are overkill for me as is.

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So, the first people should now own a FW16 7940HS. Is undervolting possible or not?

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Yes please, would love to hear this. If so, and it yields useful power savings, I’ll probably modify my order to get the 7940. Would be awesome if there was a Linux that I could have it automatically do, on battery do the undervolt, plugged into the wall go full blast to get the last bit of performance.

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If you have an order in an earlier batch, you should probably stick with what you have as to modify your CPU, you have to cancel your existing pre-order and make another one.

Undervolting is where you instruct the CPU to run at the same performance but consume less power.

Undervolting doesn’t hurt performance, in fact modern CPUs are programmed so that when under load they will increase performance as much as possible while keeping the power consumption below a certain limit and not overheating. So reducing power consumption for the same performance means the CPU will respond by increasing performance to reach the same power consumption under load.

In total undervolting reduces power consumption for the same performance, and when hit with a full load it will ramp up to the same power consumption but higher performance.

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That’s not possible.

Aw man! :frowning: I’m Batch 12, so far enough out in theory I could for some things. It’s a DIY edition though. I don’t see “Performance” or “Overkill” in the DIY configurator, but probably still something that I’d lose my batch. Which I really don’t want to do.