Minimize and CPU utilization oddness
I've always complained that Vivaldi UI is still pretty sluggish. One instance where it showed most was when I switched a YouTube video (HTML5) to fullscreen and back - it sometimes (usually) took forever to switch. I was testing this again today and comparing the performance and CPU utilization with current Opera (which is my main browser precisely for the fact that it's much more responsive than Vivaldi for me, even though I'd much rather stick with Vivaldi full time). What I did was I was playing a video on YouTube. Then I switched it to fullscreen, let it play for a while, then switched it back. Kept it playing for a while, then paused the video. Finally, I've minimized the browser window. First, here's Opera: [img size=720]http://foto.mfiala.cz/photos/i-KLRF7s8/0/O/i-KLRF7s8.png[/img] You can only really see the point where I stopped the video and then, to an extent, the point where the browser window was minimized. Switching the video to fullscreen did not really reflect in CPU utilization - there's a tiny increase when going to fullscreen, but nothing great. Now, the same with Vivaldi: [img size=720]http://foto.mfiala.cz/photos/i-ZGRghsS/0/O/i-ZGRghsS.png[/img] Those two 100 % CPU utilization spikes? That's the video switching to fullscreen and then back. Notice also how long it took - one column of the grid is 3 seconds. So switching the video to fullscreen or back took almost 6 seconds. There's also a pretty big jump when I paused the video, and then another big one when I minimized the browser window. Note that I've had the exact same tabs open in both browsers (and all of them fully loaded) and it was quite a lot of tabs - I'd say about 50. I was also running more or less the same extensions in both browsers (actually a few more in Opera, so it should have a disadvantage there). I'm running a fairly recent Win 10 install with 16 gigs of RAM (the browsers were not running both at the same time, though) on nVidia GTX 970 with latest drivers. I also have got tab animations disabled in Vivaldi. The funny thing? When I tried the same thing again with freshly started Vivaldi, I've got one result that looked pretty much identical to Opera, and the fullscreen switch was much quicker (a second or so). It still spiked a bit, but not as high. And then, after like two or three minimizations and maximizations of the browser window (in quick succession, doing nothing else in betwen), I was back to the slow and sluggish response and CPU utilization. It seems to me like there's definitely something fishy going on when you minimize the browser window. Also, when you start Vivaldi, it's default behavior is to only load tab content when you switch to that tab. Yet, if you minimize the Vivaldi window and then restore it, it suddenly starts loading all of the tabs in the background (there's no progress notification about this, but it definitely happens - if you wait a while upon restoring the window and then switch to a tab you didn't have active in that session yet, it's already loaded). Could the two things perhaps be somehow related? Note that if you don't minimize the window and just load the tab content by manually switching from one tab to the other, the performance drop does not seem to happen. The critical thing seems to be the minimize and restore action.