What laptop to use for zwift?

Hi all! I’ve started using Zwift but I have a problem. After about 15 minutes the display on the t.v. starts to change. Things like, my legs go very slowly, (no, my real legs have not slowed down!), the images of other bikes start to break up, even the clock starts to run slower! Now, I know that it’s probably my old, (about 6 years old), not very powerful laptop that can’t keep up but I can’t afford a new one. I am retired and have to justify every penny I spend. What are my options?

AppleTV is a very good option and less expensive than a laptop.

I run Zwift straight from my Samsung note 8 cellphone. You can do that or even cast it from there to a television. I cast to a 58" Sharp TV. No need for a computer at all.

BTW… The cellphone is mounted on the handlebars.