Yeah, all flavors of Linux have some sort of "System Monitor" app (OK, maybe not in Slackware, but is there even a GUI front end to use a browser with Slackware these days???)
As for Windows, there are several ways to get to what Microsoft calls the "Task Manager."
1) --->Right click on the taskbar and select "Task Manager"
2) --->Press CTRL+SHFT+ESC - this brings it up directly.
3) ---> Press CTRL+ALT+DEL - This option will bring up your standard StartUp/Shutdown wallpaper bitmap for your flavor of Windows with a number of options (dependent on your version of Windows as well as how you've set your properties in gpedit.msc...) one of which being a "button" to select the "Task Manager."
Once there (the Task Manager that is...) You'll see a bunch of tabs like in the picture below; select "Processes" and look for the offending application, in this case, look for the "firefox.exe" process, or in a 64-bit system, "firefox.exe*32".
As you can see from the screenshot, I have selected to sort by CPU usage, by simply clicking the CPU category, and then captured FireFox with 10 OTHER tabs open and waited for it to bounce up to 2% on this system; ordinarilly, it never gets quite so high, but due to how many processes I am running, tabs in FF, and about 30 plugins in FF as well, it sometimes will bounce off of 0% and up to around 2% range on this system.
Everyone running Windows really should be very familiar with the Task Manager tool, for it is the first place to start nine times out of ten to look for issues (like memory leaks, locked applications, etc...) and is a very useful tool. And, BTW, everyone, please ignore if you are familiar, I am not patronizing anyone here!
I can say the "snowflake issue" as well as high CPU load continues to elude me, for I have yet to see it here on the forum. I'll take a look at the HTML source of the page and see if I can track down what it is that I am missing out on - though I can say there's plenty of snowflakes here now and I need no more!