You may have noticed that YouTube has changed the charging method of the videos and everything looked like much slower. Prior, who had a slow connection could just pause the video and wait until the loading end to watch it without facing any crash. Today that does not happen, because YouTube has to adopt a technology called DASH.
DASH, which stands for Dynamic Adaptive Streaming over HTTP, makes YouTube send the video to your computer in several blocks instead of simply upload the entire video once. The next block is loaded only when you are finished watching the last.
It is even good for the user in some cases, especially in 3G connections to data franchise, because it saves traffic but also can cause many unwanted travadinhas and prevents you move forward or backward to any point in the video without having to upload it again. But look at that: you can disable DASH!
The magic happens with the extension YouTube Center, which can be downloaded in this GitHub page for Firefox, Chrome, Opera, Safari and Maxthon. As it is not available in the Chrome Web Store, Chrome users need access to chrome: // extensions page /, drag the file to * .crx there and confirm the installation of the extension.
After installing the extension, YouTube will display a gear button at the top right of every page, next to your username. Click the button to access the Player tab and uncheck the box Dash Playback. Ready!
If everything worked out and you have a fast connection, charging of any video on YouTube will be much faster than before; if your connection is slow, just pause the video for a while to watch it without gagging later.