RX 6650 XT: Higher coil whine with default PowerPlay settings on macOS Tahoe – PP_WorkLoadPolicyMask testing results

[ph5cold-sys]

macOS Version

Sequoia

What is your CPU's model?

Intel i5 13500

What is your GPU's model?

SAPPHIRE PULSE AMD Radeon RX 6650 XT, 8GB, AMD RDNA 2

Please describe the feature in detail.

Environment

macOS
Tahoe 26.5.1

I selected Sequoia because Tahoe is not yet available in the issue template. It would be helpful if NootRX officially added macOS Tahoe support and updated the issue template to include Tahoe.

GPU
Sapphire Pulse Radeon RX 6650 XT (Navi23)

CPU
Intel Core i5-13500

Motherboard
ASUS Z790-P D4

SMBIOS
MacPro7,1

NootRX
Latest source from GitHub, built locally.

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Feature Request

While using my RX 6650 XT on macOS Tahoe, I noticed significantly higher GPU coil whine with the default PowerPlay settings.

I would like to request:

• Official macOS Tahoe support (and update the issue template to include Tahoe).
• Investigation into the higher coil whine observed on RX 6650 XT with the default PowerPlay configuration.
• If possible, an optional PowerPlay profile (or configurable option) that can reduce coil whine without causing a large GPU performance loss.

I am happy to test experimental builds or additional PowerPlay changes if that helps.

What alternatives have you tried, if any?

I rebuilt NootRX from source and tested multiple PowerPlay configurations.

I verified every change using ioreg, confirming that the modified PowerPlay values were actually loaded by the driver.

Default NootRX

PP_DisableClockStretcher = 1
PP_DisableULV = 0
PP_GfxOffControl = 1
PP_WorkLoadPolicyMask = 16
SMU_DisallowedFeatures = 4

Geekbench OpenCL:

70394
70509

Subjective observation:

• Highest coil whine during GPU load.

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Test 1

Changed only:

PP_WorkLoadPolicyMask = 1

Everything else remained unchanged.

Result:

• Coil whine was lower than the default.
• GPU performance was also lower than the default.

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Test 2

Changed only:

PP_WorkLoadPolicyMask = 4

Everything else remained unchanged.

Verified using ioreg that the value was loaded correctly.

Geekbench OpenCL:

49408
50455
50574

Result:

• Coil whine was noticeably lower than the default.
• GPU compute performance was also significantly lower.

From my testing, lowering PP_WorkLoadPolicyMask appears to reduce coil whine, but it also reduces OpenCL performance considerably.

If there is another PowerPlay parameter or SMU setting that could reduce coil whine without such a large performance penalty, I would be happy to test it and provide feedback.

EFI.zip

[VisualEhrmanntraut]

the coil whine is literally just because of the power draw. less performance -> less power draw

[ph5cold-sys]

the coil whine is literally just because of the power draw. less performance -> less power draw

That makes sense.

I was hoping there might be a PowerPlay or SMU parameter that reduces transient power spikes or changes the power management behavior without significantly reducing performance.

Based on your experience with NootRX, is there any such parameter exposed by the macOS AMD drivers, or is reducing overall GPU power draw the only practical approach?

Also, the same Sapphire Pulse RX 6650 XT is completely silent in Windows 11 under both idle and load with the official AMD driver.

The audible coil whine only occurs for me under macOS while using NootRX. I understand this does not necessarily mean NootRX is the cause—it may simply be that the macOS driver and the Windows driver manage clocks, voltage, or power states differently.

I just wanted to mention this in case it helps narrow down where the difference comes from.