Hello,
I am having a similar problem with Opera 29 on Linux kubuntu. Everything is updated. My drive is working for 3-5 seconds every 11-15 seconds, writing something very heavy it happens only on Opera and it is worse on some web pages than on others. Pages like chess.com and gizmag.com have become very iritating to use. While playing chess, since my disk is very loud, it is bad, reading gizmag.com is iritating too, and it is not constant on gizmag, only while you scroll thru text. While I am writing this text I notice similar disk activity but only for a fraction of a second, and also freezing while writing this text, since I don't write too much on forums or anywhere I see how much more iritating this may be. There is more but i will use other thread.
