Ryzen 5900x - odd CPU Core Voltage (SVI2 TFN Readings)

[thewiredsoul]

Have a 5900x installed in a MSI X570 Unify, since the latest BIOS update i have been getting very high CPU Core SVI2 TFN readings:



Never reads a dip below 1.4.

MB Vcore:


Ryzen Master shows the voltage regularly dropping down below 1.0, sometimes much lower as does CPU-Z.

Not sure if this is a MB specific problem.

 

[Martin]

Try to enable the "Snapshot CPU Polling" option in HWiNFO, that might better reflect low power states and idle mode.

 

[thewiredsoul]

I enabled this, it does not appear to have had any effect.

 

[Martin]

Then it's a change in behavior after the BIOS update.

 

[thewiredsoul]

Okay, just not sure which tool to trust, want to make sure its not sitting at that voltage constantly. I will try reverting to old bios (though i get usb errors then), thanks for the info.

 

[Martin]

AFAIK Ryzen Master does some "magic" with the voltage reported. There's only a single voltage supplied to the CPU which is the SVI2 TFN value shown in HWiNFO. But RM does some averaging to this - most likely somehow accounts for idle states (C-State residency). IMO the value shown in RM is not a real voltage.

 

[inkforze]

Fixed this by disabling CPPC and CPPC Prefered Cores options in BIOS
5800X, MSI B550 Tomahawk

 

[Zach]

I wouldn’t call this a fix. It shouldn’t behave like this. The CPU should fall to low power stages/voltage with CPPC features enabled.
By disabling CPPC you made at least Windows agnostic of the best and worst cores. I’m not sure if this can affect overall boosting too.

Do you have the latest BIOS for your board? Also, latest chipset drivers from AMD drivers download website and Windows 10 (20H2) to latest version?

What Windows power plan are/were you using?

 

[inkforze]

I wouldn’t call this a fix. It shouldn’t behave like this. The CPU should fall to low power stages/voltage with CPPC features enabled.
By disabling CPPC you made at least Windows agnostic of the best and worst cores. I’m not sure if this can affect overall boosting too.

Do you have the latest BIOS for your board? Also, latest chipset drivers from AMD drivers download website and Windows 10 (20H2) to latest version?

What Windows power plan are/were you using?

at least this "fix" return "normal" behavior (for me)

spec:
Win10 pro 21H1 (19043.1023)
Balanced power plan (5% min cpu state, modern power option slider on mid value - default)
Ryzen 5800X
B550 Tomahawk latest non-beta bios (agesa 1.2.0.2)
Latest chipset drivers from amd site (2.13.27.501)

find this options by: reset bios to default - and disable cpu features one by one
some users on reddit confirm this behavior on other systems

 

[Zach]

I see...
The power plan is Windows default balanced or Ryzen balanced?

I would also try the 1usmus universal power plan for Ryzen. I’m using this (v1.1) for a about 1.5year.
It is specifically designed for the CPPC features of ZEN2 initially but also applies to ZEN3.

Both links are very interesting reads

Technical background and download of v1.0

1usmus Custom Power Plan for Ryzen 3000 Zen 2 Processors

In this article by our resident Ryzen tweaking guru "1usmus" we present a customized power plan for AMD's new Ryzen 3000 processors. The new power plan ensures workloads run on the best cores, which not only increases boost clocks, but also stops threads from bouncing between cores too often.

www.techpowerup.com

Follow up... and v1.1

1usmus Power Plan for AMD Ryzen - New Developments

Two weeks ago, we released the 1usmus Power Plan for AMD Ryzen processors, which received a ton of attention. Both Microsoft and AMD got involved, releasing fixes on their own. Today, we're taking a look at the improvements these patches bring, and also got a new version of the power plan for...

www.techpowerup.com

It requires some BIOS settings

• Global C-state Control = Enabled
• Power Supply Idle Control = Low Current Idle
• CPPC = Enabled
• CPPC Preferred Cores = Enabled
• AMD Cool'n'Quiet = Enabled
• PPC Adjustment = PState 0

 

[inkforze]

1. windows default balanced
2. idle voltage and freq drop must work on any power plan with allowed power saving features (like default windows balanced)
3. i just inform author of post and any other interested in this issue of possible workaround

 

[thewiredsoul]

I would point out the the power plans you linked are for Ryzen 3000, not really supposed to need them for Ryzen 5000. This really seems like a MSI specific problem.