Atlas VPN does not have any bandwidth limitations, but using a VPN can have an effect on your internet speed in one way or another.
While using a VPN, the speed that you might receive depends on many factors, such as the distance from your location to the location you are connected to, the number of users currently using the same VPN servers as well as your original internet speed.
Before attempting any troubleshooting steps, we highly recommend checking your internet speed with VPN turned on and off to see if the change in speed is acceptable. You can do that on this website.
Note: 30% drop in your internet connection speed can be expected once you have established the VPN tunnel on your device.
That being said, if you feel that the speed fluctuation is significant and imposes on your usual internet usage, you may follow these tips according to your used operating system: