It is AB,you have to set it up correctly to show you the lows and the graphs,it doesn't show that with default settings.
It's in the tab called monitoring,also you have to enable the option "show own ststistics" in rtss which is (being used as) part of AB.
1% Low and 0.1 % low means that this amount of frames have been at the number shown.
1% low 10 FPS means that 1% of all FPS measured was at 10FPS
It's just enabling it is weird for starters. Tick the cpu temperature(left hand side by left clicking once) and tick "Show in onscreen display" below as seen in the picture above. You have to do this for everything you want to monitor. Make sure to apply changes once you are done.
When you tick "show in on screen display" look at the right hand side there's a drop down box saying "text" select that and change to graph. Only choose graphs for what you need for example if you choose gpu temperature graph it will monitor your gpu temp. A spike in the graph means the temp was high there.