Another speed question

Just increased plan from 600 mbps to One Gig service.

Have Arris Surfboard SB 8200 modem and a Luxul XWR 3150 dual band router.  Desktop wired into router w/ approx 5' of Cat 5 cable.

Speed test consistently shows 500 mbps +/- download.  Seems being wired into router I should not get the loss expected with Wi-Fi.

Resterted modem already.