User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:58.0) Gecko/20100101 Firefox/58.0 Build ID: 20180206200532 Steps to reproduce: I open firefox and view task manager showing the crazy memory utilization. I tried opening internet explorer with used less than 100MB. Actual results: I open up firefox with just one tab and found the high memory usage Expected results: I expect Firefox to use around 100MB of RAM, not 500MB just on start. Memory report is attached. I've tried uninstalling and reinstalling, deleting data in appdata\mozilla folder but still the same results.

This issue is reproducible for me on the latest nightly and Fx 58.

I do not see anything specific to the Garbage Collector. Andrew, can you spot any actionable item out of this memory report?

Unfortunately, this is normal behavior with multiprocess Firefox. There's a lot of overhead now just for running Firefox at all, so if you don't have many pages open, you are paying mostly overhead. Looking at the memory report, there's the main process (175MB) which deals with the UI and talking to the OS, there's a content process (123MB), which has about:newtab and a Reddit page, there's a process for web extensions (56MB), and another content process (13MB), which I think is there to make it so that if you open another tab it will be faster. The main process and content process do look a little high, but I'm not sure why. We are trying to reduce the overhead of content processes in bug 1436250, but it is not easy.