I have been using software written in Qt [0] across different OS. Many of them were written specifically to be used in GNU/Linux, such as Okular [1] and QBittorren [2]. Others, such as VLC [3], were later shipped to other OS. In the case of VLC, only the GUI was written in Qt.<p>I have noticed that Okular and Qbittorrent were very energy efficient in GNU/Linux. But I didn't expect it to be the case in other OS such as MacOS.<p>Recently, I used Homebrew to install Okular on MacOS, and I compared it to other PDF readers such as Adobe Acrobat Reader and Skim. Okular was superior in terms of energy consumption.<p>RESULTS: Energy impact for 12h:<p>Adobe Acrobat Reader = 0.9<p>Okular = 0.4<p>QUESTIONs: Is this always true? Do Qt software always perform good in terms of energy consumption, across OS? Why is that?<p>[0] https://en.wikipedia.org/wiki/Qt_(software)<p>[1] https://en.wikipedia.org/wiki/Okular<p>[2] https://en.wikipedia.org/wiki/QBittorrent<p>[3] https://en.wikipedia.org/wiki/VLC_media_player
I seem to recall from my work with low power microprocessors, it had to do with how your compiler instructs the cpu to preform bit wise operations. I believe it has something to do with the internal pullups drawing power due to the state of the data in the register at rest.<p>Eg it is more efficient(or less) to instruct a loop to count down from 50 to 0 rather than up from 0 to 50, both methods result in 50 cycles but one is more efficient.