I prefer the netflix speed test solution fast.com as it gives more consistent speed checks.
However the 1GB speeds not only rely on the speed test site you are using but the age of your network card / chip in your devices
I work from home for the IT department of a local company and a lot of the older kit which goes through my hands can't get anywhere near the 1gb speeds, due to older networking tech within and slower processors, which combined, slow the overall maximum network speeds on wired and wireless they can achieve.
Also if your testing on WiFi, the channel number in use can have a huge difference in traffic speeds because of surrounding congestion.