comparing e10s to non e10s we have what looks to be a 2.9% tscrollx regression: :( tscrollx 3.0 +/- 2% (6#) [ +2.9%] 3.1 +/- 2% (6#) unfortunately we don't have data for winxp/win8. Quite possibly some --sps-profiling will allow us to see what is going on here.

from: https://treeherder.mozilla.org/#/jobs?repo=mozilla-central&revision=aad95360a002&exclusion_profile=false&filter-searchStr=talos we have: Win7: :( tscrollx 3.0 +/- 2% (7#) [ +3.7%] 3.1 +/- 2% (7#) WinXP: :( tscrollx 2.6 +/- 12% (7#) [+591.6%] 18.2 +/- 2% (7#) notice the windows xp nasty here!

On both win7 and xp, e10s is now better than non-e10s for tscrollx summary results. https://treeherder.mozilla.org/perf.html#/graphs?timerange=1209600&series=[mozilla-central,c33eba52ac3ad7d976bd2a972930490395f20b46,1]&series=[mozilla-central,3e4c0b1bffd401a58b2e625168176cffeb90c758,1]&series=[mozilla-central,e5c782b789ec02e8add7dae8c97ca3f42ed46442,0]&series=[mozilla-central,c3eb69f0719aacca596bca0626205e4b30953034,0]