What will use more CPU power: play music in iTunes or play from SoundCloud in a tab in Safari?

What will use more CPU power: play music in iTunes or play a YouTube music video + slideshow in a tab in Safari?

What will use more CPU power: play music in iTunes or play a HD YouTube music video in a tab in Safari?

(scroll down)

In all 3 cases iTunes is using more CPU power. I am not streaming with iTunes, not using iTunes Music, only use it for playing good old mp3 files, offline.

So streaming files over the internet using SoundCloud or YouTube in a tab is less stressing the CPU. Something I was not expecting. I used my trusty old (late 2013) MacBook Pro Retina running El Capitan.

In all 3 cases I had 4 tabs open in Safari:

• Google Inbox
• medium.com
• melodiefabriek.com
• either soundcloud.com or youtube.com

So even with 4 tabs open, Safari is a much “lighter” piece of software than iTunes.

Offline versus streaming. Interesting, right?