Hi, I've started comparing the xtraces of dillo1 and dillo2 during scrolling a long, _empty_ page (just 100 times "<br>"). The dillo2 trace contains the request 000:<:0392: 28: Request(62): CopyArea src-drawable=0x00a0000a dst-drawable=0x00a0000a gc=0x00a0000b src-x=0 src-y=74 dst-x=0 dst-y=73 width=1009 height=631 (A similar line appears in the previous traces of Johannes and mine.) For dillo1, I get 000:<:05b6: 28: Request(62): CopyArea src-drawable=0x00a00087 dst-drawable=0x00a0006d gc=0x00a00008 src-x=0 src-y=645 dst-x=0 dst-y=645 width=990 height=10 I don't have a detailed understanding of what's going on, but I find the difference in the "height" parameter remarkable. It seems that dillo2 copies an area - roughly the whole screen - which is 60 (!) times larger than that copied by dillo1. 60 could also be the performance difference we observe. Cheers, -- Matthias Franz