Christopher Dobey Christopher Dobey

Safari supports 4K YouTube

Chrome 4K HDR

Safari in macOS Big Sur at last supports 4K YouTube playback (i.e. VP9 codec) but still no HDR option such as Chrome has supported for a while now. Looking at CPU/GPU usage we see that 4K HDR in Chrome uses a much more significant amount of resources than 4K SDR does in Safari. Whether this is due to Safari being better optimized than Chrome or HDR being much harder to decode is yet to be deciphered.

HDR v SDR
Read More
Christopher Dobey Christopher Dobey

Canon R5 / 8K RAW

Canon R5

For the first time a mirrorless camera achieves not only 8K but 8K in its full RAW glory. For comparison the 5.9K Canon 1 D X Mark III files cannot be played in realtime / full resolution with the 18 core iMac Pro. 8K will therefor be that much harder to crunch. There is hope though; a week before the R5 launch, Blackmagic released Resolve update 16.2.3 with full Apple Metal support providing a performance boast that will be tested once R5 RAW footage hits the internet.

But do we need 8K? Yes we do!

4K files viewed on a 4K monitor look better when the original footage is shot in 8K. This is due to the nature of the Bayer Filter process and result of supersampling. Both of which are topics worth researching. In essence a larger resolution video packed down to a lower resolution screen will show less noise and more color fidelity.

Read More
Christopher Dobey Christopher Dobey

No Apple 4K Content Download

According to Apple support, 4K video cannot be downloaded for offline viewing, regardless of your device - ‘You can download a copy of an HD movie to your iPhone, iPad, iPod touch, Mac, or PC, but you can't download a 4K version’.

Quite a shame since the 16” MacBook Pro sports a quality 3K [3072x1920] display and the 12.9” iPad Pro is not far behind with 2.7K [2732x2048]. Hell, even the 6.5” iPhone 11 Pro Max outpaces 1080p with a solid 2.6K [2688x1242].

Read More
Christopher Dobey Christopher Dobey

iMac Pro 2017 Fan Noise

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.

Read More