What drives down video performance?

Hey,

Okay, I bought my laptop (as you can see it on my signature) around three months ago.

It was perfect, bliss, especially the graphics.
Yet, I have the impression that the more time passes,
the more the quality of the video goes down.

The only "videos" I actually watch are on YouTube, and while in the past I was able to watch perfectly clean videos... now (using Firefox latest version) its progressively starting to lag the video (despite pressing "Play" after having downloaded the entire video)
(e.g. When I have many programs open. But previously, with the same programmes, it did not happen.)

What do you think is the cause of this?

What does generally cause to decrease the quality of video?

Thank you

P.S.: Ever since I bought the laptop, I installed only following programmes. Anyway, even after I had installed all of these, video was good. It started going down/lagging only recently.

Mozilla Firefox
FileZilla
avast!
OpenOffice.org
7-Zip
Audacity
Printer software
and the usual software updates.

 

I don't think your computer is the problem. This sounds like it might be a bad internet connection, or the latest version of Firefox might be the problem.

 

Since you're using youtube, I'll second the idea that it's just a connection thing. Youtube has always been that way for me. One day it is smooth and the next I can't get the videos to download all the way.

 

I see. I've noticed that as well.

But I was talking about already downloaded (red bar completed) videos.
Sometimes it becomes a bit pixellish, and while I do other things, the sound flickers a bit.

 

I still think it's probably just the videos themselves, and nothing to do with your computer. You could try going to the processes tab and seeing if any program is hogging the CPU, which I guess could result in decreased performance.