The researchers pointed out that these are early days of the 5G era and the 5G maximum speeds are expected to continue to increase as the service expands its reach.
The difference between 5G users' max speed and 4G users ranged from 2.7 times as fast in the US, 2.6 times as fast in Switzerland, Opensignal VP Analysis Ian Fogg said in a blog discussing the findings.
But in Australia, the maximum speed experienced by 4G users was so fast that the maximum 5G speed was actually slightly slower than the maximum 4G speed.
For the study, the researchers looked at the maximum real-world speeds seen in eight countries which have launched 5G services - Switzerland, South Korea, Australia, the United Arab Emirates, Italy, Spain, the UK and the US.
"It's unsurprising to see that the current 5G maximum speed is so much greater in the US, because operators there are already able to use mmWave spectrum for 5G," Fogg said.
"This is extremely high capacity and extremely fast spectrum but has very limited coverage compared with the 3.4-3.8 GHz 5G 'mid band' spectrum typically used in most of the other countries we analyzed where mmWave spectrum is not yet available," he added.