I got stuck with writing a responsive website, and was researching (read looking for code to cut & paste). I had only 15 tabs open in IE11, 4 Yr old Laptop, i5, 8GB, 64bit. The fan was going nuts, like it would if I was cracking passwords or rendering 3D.

I went looking for ways to see what tabs were the main culprits and actually pretty shocked.

first shock was the great tool, built into IE11 to show each tabs performance - great. Press ctrl+shift+u or Alt+T and choose performance dashboard. This tab I am writing the post on is showing 105.4MB memory and between 2% and 6% cpu.

If you click on one of the 4 results, you get a graph of recent activity.

Another tab had a short tutorial, comments and ads, and was 360MB memory and 21% CPU.

considering the content of these pages struggle to go past 2 MB, this is crazy.

to put this usage in perspective, I build a lab of 8 sets of ncomputing pods. each pod consisted of 1 PC, 1 ncomputing card and 3 ncomputiing breakout boxes. connect a Kb, mouse and monitor to each box and you now have 4 separate workstations running off 1 box. ok, so login (domain login) to all 4 workstations, open a 2 page word docx, excel xlsx, powerpoint pptx and access blank file on each of the 4. The CPU usage of all 4 workstations combined never went higher than 10% apart from a couple of spikes.

if you find yourself with a very slow PC and fan going nuts, try finding the offending tab/tabs and killing it/them.

So this all being said, you would think a high priority would be coding good, fast websites. but not a single tutorial I have seen thus far mentions memory or CPU usage of the page, how to check, or even TO check. The big and only focus is that it MUST now be "responsive" and the meaning of that is to run on all shapes and sizes of devices. In my view "responsive" means something else and a better word would be "adaptive".

Back in Uni we did do some stuff in media studies that would focus on page load times, but this looks to have gone the way of the Dodo.

further to this, if you do want to have a metric tonne of tabs open in a browser, this may be the way to do it:
https://chrome.google.com/webstore/detail/the-great-suspender/klbibkeccnjlkjkiokjodocebajanakg?hl=en

Basically you can set a time limit for tabs that are not in focus to be suspended, freeing up resources until you switch back to them. I have had a play with it, and yes seems pretty good.

If any of you are like me when I get to searchin' ... I like to cntrl+click on a heap of results and afterwards go through them. IE11 chokes on it.

There is a write-up here
http://thehackernews.com/2015/06/chrome-browser-fast.html

to much commication in google chrome going back to them.

i would not trust it to many SVCHost processing running all the time

firefox is a little bit better