up-to-date win 7, latest firefox (51.0.1, 32-bit) refreshed a couple of days ago, 8GB, 66% ttl physical memory utilization, 1-2% cpu utilization.... with 9 firefox windows open, each with a single tab, no active content (that i'm aware of), the entire machine sitting idle for 5 minutes.... firefox pages at the rate of between 500 and 3000 faults per interval, according to Windows Task Manager. why is it doing that? there are 110 other processes running, and the total page rate from all of those is typically <10. also.... before the refresh, i noticed that once the working set crawled above 1GB (with maybe 16 tabs distributed across 10 windows), loading a relatively simple new page in a new tab, which normally takes a second or so, was taking 10 seconds or longer, which is inordinately long. any ideas?