iMac Pro
2017, Xeon 18-core W-2195, Vega 64X, 64GB DDR4 2.6 GHz
Environment Peak Noise Level: 29 dB-A
Dual fans controlled manually with iStat Menus™ v 6.4 Measurement taken with iPhone XI Pro Max and Decibel : dB sound level meter™ v6.0.3 on iOS 13.4.5 Beta from 3’ away.
0% | 1100rpm | 29 dB-A
25% | 1450rpm | 30 dB-A
50% | 1800rpm | 32 dB-A
75% | 2150rpm | 37 dB-A
100% | 2500rpm | 41 dB-A
CPU only intensive tasks like Handbrake 1.3.1 peak all 18-cores at 100%, but even after 30 minutes of continuous rendering both fans are spinning at just 15% (barely audible). Peaking the GPU at 100% with heavy rendering such as exporting noise reduced BRAW in DaVinci Resolve 16.2 makes both fans kick up to 100% (loudly audible) in a matter of seconds. The Vega 64X has a TDP of 250W while the 18-core Intel W-2195 is only 140W, suggesting why the CPU needs less cooling at 100% than the GPU.
MacBook Pro
2019 16” i9 8-core, AMD 5500M results for comparison.
0% | 1750rpm | 29 dB-A
25% | 2700rpm | 30 dB-A
50% | 3600rpm | 34 dB-A
75% | 4500rpm | 40 dB-A
100% | 5400rpm | 43 dB-A
* MacBook Pro 16” is designed to spin each fan at a slightly different speed to cut down on cumulative noise of the same frequency. An average between each fan was taken to calculate rpm.
macOS 10.15.4 Stable release 19E266.