Websites that run fine on Safari will consume RIDICULOUS amount of CPU time when open in tabs on Firefox. This is NOT a website issue. This is a FIREFOX issue. Doing a little bit of searching on the internet, this has apparently been an ONGOING problem for FIREFOX. I am tired of all the "possible" explanations, especially after ruling them out. NO, it's NOT "add-on" or extensions. NO, it's NOT "preferences." NO, it's NOT "the website." IT IS FIREFOX. I am ready to PERMANENTLY DELETE Firefox—just like I did with Chrome—and NEVER look back. Sad. I remember the days when Firefox was my only browser. Too bad it's developers seem (really) inept.