High Resources Use
I love Vivaldi for Mac, but lately I've been having very high resource use -- my computer fan will be loudly humming and Vivaldi Helper will be using 90+% of my CPU cycles (according to Activity Monitor).
Hoping the next update calms things down a bit!
Is this happening all the time or just if you're watching streaming video?
Does vivaldi://gpu reveal anything interesting? This status page will show if your graphics driver has been blacklisted and if GPU hardware acceleration got disabled as a result.
If you open Task Manager from the Tools menu in Vivialdi, you can see which website (or extension?) is actually responsible for almost maxing out your CPU. Just like in Activity Monitor you can sort by CPU utilization by clicking on the CPU column header.
@NSSynapse FYI, shortly after installing the Vivaldi 1.10.845.3 snapshot, I experienced a prolonged CPU spike on my system with a fairly new/clean profile that occurred for no apparent reason. The fans on my MacBook were on full blast. It only happened once and hasn't happened since. Very strange.
Also, many users on all platforms have recently found their GPU's blacklisted and Vivaldi falling back to software-based rendering. CPU spikes while watching video are an initial sign that this has occurred. (Another symptom on macOS is the inability to decode H.264 video streams. Bug filed: VB-28551)