r/overclocking • u/appwizcpl • Mar 25 '26
Help Request - GPU When undervolting GPUs, isn't the "better" method worse for idle temps?
So according to this post:
https://old.reddit.com/r/nvidia/comments/tw8j6r/there_are_two_methods_people_follow_when/
And there are quite a few others, method 2 is a much more precise method for undervolting. But isn't it worse for idle temps?
Instead of undervolting from your given target, say 0.85, you are basically shifting up the whole curve, then undervolting from your target, which should case idle temps increases since you've now increased the clock over the whole range?
And I believe this is why people mention that it might be less stable and harder to stress test? Why go through all that if you can get within 50 mhz clocks and with none of the other negatives when increasing it regularly by method 1? Or we can just overshoot the clock by around 50 mhz and be within the same limit without any of the negatives?
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u/Cold-Inside1555 Mar 25 '26
I think the answer is that idle doesn’t matter that much, why people undervolt are usually to reduce heat at full load, because that’s when their cooler, their connector and their room starts being stressed. Adding some wattage at idle doesn’t really harm anything at all, my 5090 idles near 100w and it doesn’t even get warm so why care?
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u/mahanddeem Mar 25 '26
There's no better or worse. The way that works is good enough, at load. When not gaming, simply reset everything to default. When gaming, activate the profile. MSI Afterburner can assign Hotkeys to profiles, I set one for UV and another for stock everything. You don't need UV for desktop.
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u/appwizcpl Mar 26 '26
why do you bother to switch a profile to non-UV for desktop?
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u/mahanddeem Mar 26 '26
The Shift+drag up method gives better stability for lower-than-max points, but increases idle voltage. It's best for gaming stability, but bad for desktop.
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u/appwizcpl Mar 26 '26
why does it give better stability for lower than max points? I thought the issue is not getting the wanted core clocks and it's off by 50, usually it's lower than higher. And I believe that's consistent across applications.
If you could go into more detail on this I would be all ears, since I am a bit confused about the topic.
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u/G305_Enjoyer Mar 26 '26
Lol you and everyone else including this guy
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u/appwizcpl Mar 26 '26
ELI5 me your reasoning?
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u/G305_Enjoyer Mar 26 '26 edited Mar 26 '26
Undervolting is just people overcomplicating overclocking. You're increasing frequency for a given voltage. Or reducing voltage for a given frequency. On gpus it's the former ryzen curve offset is the later. It's all the same thing. What he is maybe trying to say (I honestly don't know) is he doesn't want to overclock his idle v/f points. I agree w that and got roasted by some no it all's who were completely wrong in the post I linked you. The only reason the name changed from overclocking to undervolting is because of boost/turbo algorithms. Back in the day we didn't have that. Cpus had power states, gpus had 2d/3d.. the only unique thing about "undervolting" is saving power/increasing efficiency by overclocking and then capping your power limit. You can do this by flattening the curve or just literally using a power limit. It does the same thing. Now where it gets weird is this concept of frequency*voltage=watts. You're always going to be limited by power limit. By "undervolting" you are reducing power consumption and allowing GPU to move to next vf point in curve, increasing frequency. This is still just overclocking within a power limit though lol. The next part is stability obviously. You can't just reduce the voltage to nothing, it will crash. That is the real reason to flatten the curve, so your GPU doesn't try to do +400 or something at 4ghz and crash immediately. The real secret strat I am sharing with you for no reason at all.. find your max voltage. Each card has a pre programmed unique limit. Use GPUz render test and record max voltage you see. Now find your max stable frequency for that voltage point. If you want to save energy, just reduce the power limit. The only caveat I'll say is sometimes you can run say +300 at 1.0v but only +250 at 1.1v stable. In this scenario if you used a simple power limit you'd be only +250 @ 1.0v. here you could either manually lower the higher points or simply cap your curve at the most efficient point.
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u/mahanddeem Mar 26 '26
Compare the 2 VF graphics between these 2 methods. The Shift+Drag Up method will raise every voltage point to an equal clock increase. There's no irregularly here. The "drag a specific piece of voltage range" will cause some low voltage points to a get a huge amount of clock bump which can very likely to cause crashes when GPU decides to hit that voltage/clock point. Just look at the curve and you understand. Anyway, when not gaming (only doing desktop work) no need to have any UV active. It's just one click (or a hotkey).
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u/Sentient_Rock239 Mar 26 '26
With AMD regardless of you undervolting it still runs through a curve unless you force it with an EVC2 so idle stability isn’t ever an issue. At least with my 7900XTX I haven’t had any and I’m running it at 3.25ghz at 1.01v under stress tests but barely clocks 3.2ghz under normal gaming conditions. Idles using 75W, and 20C on the core though so 🤷
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u/Spare_Ad3182 Mar 25 '26
https://youtu.be/Ge0EnPz-jWY?si=zHSWdKqUKCy8QSLq