This requires some explanation. I have 6GB of RAM, and am running Windows 7 64b. I just updated to v115 from v56esr. I was using an extension that broke when the quantum update came out, and I wasn't willing to let go of it so I stopped updates. When the occasional website stopped working on the old version I would use Chrome for that website, but Firefox has always been my preference. Chrome was such a memory hog that I couldn't have more than a dozen tabs open at once before it crashed, and for me that is unacceptable. At this point however, enough websites have ceased to function in Firefox that it was worth it to me to update. After updating I found that Firefox uses just as much memory as Chrome. Where I previously could have 30 or 40 tabs loaded at once before running out of memory, now I only get about a dozen. Question: In what version(s) did the memory consumption drastically change? What version can I revert to in order to bring memory consumption back to a manageable level? What other settings can I tweak to reduce memory usage? (For example, can I automatically reject loading of subframes?) Please Note: - I use adBlock+ and I have made a habit of turning off tracking and rejecting cookies and notifications everywhere I go online to prevent excess resource usage, among other things. - I use very few extensions so there isn't really any memory to save there. - I understand that my computer is old and should be upgraded. Telling me to get a new computer or add more RAM is unhelpful and will not be appreciated. - I also understand that running out of date software is a security risk and is not recommended. I don't care, so don't bring that up. - And I also understand that I am a tab hoarder. Because of the way I work I typically have 50-100 tabs open, but I periodically close it so as to unload everything and usually don't have more than about 30 active tabs at once. - I know that some websites (particularly those with lots of subframes) use much more than other sites so my memory usage is entirely dependent on which sites I have open, and I know that I can open the task manager to close/unload unnecessary tabs and subframes. Having to do that frequently is a pain, and it doesn't work if I need all the tabs that are active.