The purpose of performing a bandwidth speed test is to determine how fast the data transfer is on your computer or network. If Comcast is your internet provider and you want to check your sprrf by using their site, it would seem to be an easy task —  just enter the site and click the links —but other factors, mainly hardware and software, can alter the speed test.



Several programs installed on your computer can cause a slower transfer bit rate when determining bandwidth speed. Firewalls, antivirus programs, and any administration tools that may be checking Internet connectivity can slow down the process. These programs check each bit of data as it comes into the computer and, in some cases, adds extra data to help with encryption. Before running a speed test, shut all of these programs off.


All wireless devices add latency to bandwidth speed. The latency is an increased amount of time between each packet of data. This process slows down the bandwidth speed. Connect the cable directly to your computer for the most accurate bandwidth test.

Each device added into the network adds latency. Data typically has to go through a modem and a router before it gets to your computer. If there other devices, switches, or servers involved, the latency will increase for each device.

Testing the Upload Speed

To run a bandwidth speed test using Comcast Internet, do the following:

  • Disable any software that can slow down the test.
  • Disconnect any hardware that can cause latency issues.
  • Go to the Comcast Speed Test site.
  • Click the server on the map closest to your location.

A new screen appears as the site tests your ping rate; then it continues, verifying the download speed and lastly the upload speed.

The main thing to consider when testing the bandwidth speed is the purpose of the test. Do you want to know the speed of the bandwidth to verify that you are getting what you pay for? Or are you testing to find out the maximum speed for games or other utilities programs?

If the reason is for the latter, then there is no reason to remove the hardware and disable the software. You should test the bandwidth speed under normal circumstances with everything connected and all programs running. Don’t forget that shutting down antivirus programs and firewalls make you vulnerable to security threats, so be sure to turn them back on afterward.