ExtraFPS performance does not change when using menu Advanced -> Set Window Size to a lower resolution. Older versions 7.1.8 and 6.6.17 do. Attached 4 screenshots showing the behavior on 7.1.8 and 7.1.11. This only happens when we start noticing the bug described @ https://feedback.secondlife.com/bug-reports/p/deltafps-extrafps-viewer-slowdown-coming-back-to-focus . ( Maybe this ticket should be attached to the other one, I have no idea if they are related) In fact, another interesting observation.... when we notice that bug... the viewer when out of focus, FPS goes down to 17, 18 fps instead of the usual 22 fps. There is something holding back ExtraFPS within the rendering engine, being just weird when it comes to performance, the viewer has a will of its own (ExtraFPS gets "pissed off" too easy! Needs some coaching! heheheh ). Along with the "bug" described @ https://feedback.secondlife.com/bug-reports/p/deltafps-extrafps-viewer-slowdown-coming-back-to-focus it seems to be worst on ExtraFPS with long sessions... that same 100 fps shown in the screenshots, after a 10/15 minute session with normal use, comes down to 65 at that same location, same rendering (landing point), its worst when coming from a login from 6.6.17 with the official viewers if you dont clear cache between sessions. ( I have no idea how it affects Firestorm, but I assume its relevant, since a lot of people is trying the new PBR viewer ). This contributes to that "bad" taste using the PBR viewer when it comes to performance, even on a machine that in theory supposed to push it really well, I assume it is much worse on low end machine, even though is harder to compare or notice (100 to 65 vs 35 to 25)... [EDIT: Added 2 snapshots showing that bug related (hijacked my own post), one with viewer "upset" showing the related bug above, another with the viewer in a good mood! @ http://maps.secondlife.com/secondlife/Lost%20Unicorn%20Gallery/125/111/22 , which is a very detailed region showcased at the destination guide, 6.6.17 shows 45 fps for that same region, same machine... basically that is what we are asking other users... switch to PBR, your fps can go from 45 fps at a region that you like down up to 19 depending on the viewer mood at the time! Not going to happen!] PS.: Its really easy to like the final rendering for PBR content and all the effects (I do), but even easier to hate performance compared to the old engine, which was not as fancy, not even close... but still very enjoyable.