Live streaming issues

Hello guys,
probably not the right section but I couldn't find the adequate one anyways.
I've been struggling big time with live streaming online, no issues on YouTube but on other websites, freezes every 5-10 seconds, impossible to follow anything.
I know it's not the connection speed, I don't think it's the RAM (8GB easily enough), I'm not downloading anything else or any other software open, I DO have issues with Flash (which I reinstalled just now) and it's the same issue on Firefox as Chrome.
I'm on 10.8.5 btw.
Windows explanations on forums are never relevant to me. Can anyone help, please ?

 

nope ! Like I said, I make sure nothing uploading/downloading, or any program's running in the background. It's not RAM, I can open up an HD video with VLC during that time, and that'll be fluid - it's something to do with browser/video...?...