If you've never hit 100Mbs ever (and get around 90Mbs) then it's showing that you are limited your end. Never going above 100Mbs indicates a 10/100 connection and not a full gigabit connection needed for speeds over 90Mbs
If you are testing wireless, test wired. If you have been testing wired, then look at the spec of your ethernet ports on PC/LAN card/Ethernet cable spec.
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