Question How to tame a wild 3900x?

OllympianGamer

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Dec 22, 2016
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Seriously I don't understand the stock settings for this cpu. I've had it in multiple systems with various aios and it seems to always have a 1.48 vcore with pbo on or off and the temperature although ok seems rather high (40°c idle) (75°c load) with a h100x.

The clock speed at idle is usually around 4.3ghz on all cores even with cool and quiet on.

So at the minute I've got a x570 asus rog strix, I was sort of hoping that moving up to the newer platform the motherboard would be able to set the cpu correctly but it isn't any different from a b350 or b450.

I'm fairly inexperienced with amd cpus so if anyone can give me recommendations for voltage and such in the bios I would appreciate it.
 

OllympianGamer

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Dec 22, 2016
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I don't see any issues with anything you've described. But it wouldn't hurt to make sure you have the latest BIOS and chipset drivers, along with all Windows 10 updates.
Yeah I'm all good with updates. Performance wise it's all good it's just when looking at HWinfo the cpu just doesn't look stable, the temperature, clock speed and voltages fluctuate massively even at idle but if that's how it is then fair enough.
 
Seriously I don't understand the stock settings for this cpu. I've had it in multiple systems with various aios and it seems to always have a 1.48 vcore with pbo on or off and the temperature although ok seems rather high (40°c idle) (75°c load) with a h100x.

The clock speed at idle is usually around 4.3ghz on all cores even with cool and quiet on.

So at the minute I've got a x570 asus rog strix, I was sort of hoping that moving up to the newer platform the motherboard would be able to set the cpu correctly but it isn't any different from a b350 or b450.

I'm fairly inexperienced with amd cpus so if anyone can give me recommendations for voltage and such in the bios I would appreciate it.
It all seems fine to me too, except not sure what you mean that it 'always have 1.48VCore'. Is that truely a constant reading? or constant peaks up to 1.48 then back down? Which is normal when Ryzen's boosting is working correctly.

It's perfectly OK for it to have peaks up to 1.50V when at low/no loads but it should also have a lot of low-voltage time too. An average reading (HWinfo64 has one) on my system over about 10 seconds min. at an idle condition with a browser open should be 1.35V or less with many minimums (graphed) of 1.00V and less. With absolutely nothing open (except HWInfo of course) average voltage will hover around 1.00.

Ryzen's very active with aggressive boosts for performance when needed and a rapid return to a deep sleep state as soon as it can to reduce power consumption. It does this on 1mS time cycles, way way faster than any processor previously. And it actually goes lower than 1.00V, but nothing can monitor conditions when a core goes into a C6 deep sleep state so it just stops at last condition read.
 
Last edited:

TJ Hooker

Titan
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Yeah I'm all good with updates. Performance wise it's all good it's just when looking at HWinfo the cpu just doesn't look stable, the temperature, clock speed and voltages fluctuate massively even at idle but if that's how it is then fair enough.
Keep in mind that Windows is often doing stuff in the background, you're rarely at true idle. Plus the monitoring software itself will result in some usage. Modern CPUs are designed to rapidly adjust their frequency/voltage (which in turn affects temperature) to quickly respond to tasks and then quickly return to lower power states.