Created attachment 153435 [details] Video fo the slowness SUMMARY When I zoom the map a lot, moving around is very slow (I would say mostly unusable). STEPS TO REPRODUCE 1. Download https://www.parconazionaledelvesuvio.it/wp-content/uploads/2020/05/Parco-Naionale-del-Vesuvio-Guida-ai-Sentieri-del-Parco-2020-05.pdf (there is a size limit to bug reports of 4 MB, the file has 6.7 MB, can it be somehow uploaded so it does not get lost?) 2. On the first page, zoom to at least 200 % 3. Press right-mouse-button and drag the map to pan it around. OBSERVED RESULT It is quite slow. When I pan to an area far from the original display, white screen is displayed for quite some time before ti is displayed. When I go back to the original area, it is not cached, instead I see again white area that takes seconds to render. See videa attached EXPECTED RESULT I would expect it to all be fast and smooth. When I open the PDF with my browser (Vivaldi) it is fast, so it can be fast. My machine is quite fast (Thinkpad X1 Extreme gen 2, 8-core CPU etc.) As can be see in the widget above the window, just one core is 100 % used, the others just sit there. I turned on the greedy setting in PErformance tab of the settings. The second page of the PDF is notably faster. SOFTWARE/OS VERSIONS Linux/KDE Plasma: Kubuntu 22.04 (available in About System) KDE Plasma Version: 5.25.5 KDE Frameworks Version: 5.98.0 Qt Version: 5.15.3