I think there's a problem with performance in Sailfish generally, it's not browser specific, and shouldn't be Qt specific. Per the browser performance testing I did on the Jolla & Nexus5, FireFox running inside Alien Dalvik VM on the Jolla is faster than any browser on the Nexus5 running Sailfish (SD800 is miles faster than SD400 in Jolla), let alone SF on the Jolla. This shouldn't happen. I tested UP performance on the Nexus5 too ... it also uses Qt, QML and libhybris for hardware adaption. If there are inherent issues with them, then they'd suffer too. However, Octanev2 results for Ubuntu Phone's default browser are faster even than any browser running in a fast, lightweight AOSP based Android ROM on the same phone (vastly faster already than Nexus5 w/ SF). So there shouldn't really be a reason why Sailfish is so slow, if UP can do it. It looks like SF has a hard time loading the CPU properly. Maybe task scheduling is broken or poor? Did the testing in April, nothing has changed with 1.1.7 as I tried it last night; was hoping that as 1.1.7 supposedly carries a lot of the technical underpinnings for v2.0, they might have done something. I'm sure Jolla have been aware of it forever, and I did pass the results on... but they've never acknowledged the issue or added potential improvements to the new roadmap - mainly I suspect because it differs from the narrative that SF is fast, efficient and lightweight (something that couldn't be further from the truth ATM with RAM hunger and poor performance) ... or maybe they don't know how to fix it / what the cause is.