Is there any impact on CO/PBO settings and voltage stability when using lighter CO levels in Ryzen 7 9800X3D?
Is there any impact on CO/PBO settings and voltage stability when using lighter CO levels in Ryzen 7 9800X3D?
Here’s a revised version of your message:
Hello everyone,
I’m seeking some feedback or understanding about the performance of my Ryzen 9 9800X3D while adjusting PBO/CO settings. The system details are as follows:
- CPU: Ryzen 9 9800X3D
- Cooling: NZXT Kraken Elite 360mm
- Motherboard: ASUS ROG Strix B650E-E (latest BIOS)
- Memory: 2×16 GB DDR5-6000 (EXPO I)
- Software: All drivers and system tools are up to date
Current OC settings:
- Curve Optimizer: -30 all cores
- PBO: +200 MHz CPU Boost Override (typically +150 MHz for Cinebench)
- PBO Enhancement Level 1 (90°C limit)
Performance and stability results:
- Cinebench R23 (Normal priority): ~23,950 points
- Cinebench R23 (Real-time priority): ~24,150 points
Result: Similar scores whether boost is at +150 or +200 MHz
- Vcore under load: ~1.265–1.280 V
Stress test outcomes:
- OCCT Linpack 2019, OCCT Memory, CPU Extreme (per-core) – fully stable
Voltage behavior observations:
- Reducing CO from -30 to -10 causes voltage spikes of 1.34–1.37 V during light loads
- This leads to reduced stability despite a lighter undervolt setting
- This outcome is unexpected:
✔ Aggressive CO (-30) → lower, stable voltage
✘ Lighter CO (-10) → higher transient voltage and instability
Screenshots included:
- Idle: https://imgur.com/jAr8Dsf
- View: https://i.imgur.com/jAr8Dsf.png
- Idle #2: https://imgur.com/O0WBAq3
- View: https://imgur.com/O0WBAq3
- Load: https://imgur.com/0xwZ9FR
- View: https://imgur.com/0xwZ9FR
Load #2: https://imgur.com/sA4uFU1
My question:
Is this typical for X3D chips running on Zen 5? The peak voltage at -30 appears normal, but -10 causes excessive spikes and instability. Anyone else noticing this kind of reversed voltage response with CO adjustments?
Thank you in advance for any advice or insights!
You need to verify how your load line calibration functions, which influences the voltage variations based on the current moment relative to the CPU's requests. Under light loads, there is greater power margin and because amps are at their maximum, the voltage increases significantly. Lower your single or few core boost overrides to a lower frequency so it doesn't attempt to deliver excessive voltage.
Tested at +75MHz, but outcomes remain identical regarding Vcore spikes... quite unusual. I'll review the llc in the BIOS.