Jonathan Morrison has a great video about editing 4K video on a 12” MacBook; it’s a response to a similar video from Linus Tech Tips about editing 4K video on an ultrabook running Windows. Linus is unable to complete the task on the Windows machine, whereas Jonathan was able complete the task with the MacBook (the MacBook is also under-specced relative to the ultrabook). This outcome is particularly rich since in a previous video from Linus he makes blanket statements about Macs being slower than PCs.
This is a great example of the difference between specs and real world usage, the ultrabook comes out ahead in specs, but the MacBook performs better in real world usage. And it wins in the most decisive way possible: By making an impossible task possible.
The differentiating factor is that Jonathan uses Final Cut Pro, whereas Linus uses Adobe Premiere Pro. Final Cut Pro uses background rendering and Intel Quick Sync Video to stay responsive with less resources.