I am experiencing unreliability of the Unreal Editor in version 4.10.4 while attempting to edit a fairly large map comprised of lightweight streaming tiles. The editor grinds to a crawl, and the memory consumption is up to 19 gigabytes.
1st problem is importing a mass of landscape tiles into a new level, there are 1600 tiles (40 x 40). The tiles themselves only have a terrain size of 505, and no textures are imported during tile import. The editor starts of really fast, importing almost 40 tiles per second, but it starts to slow down. Now its about 3/4 of the way through, the tile import is now taking over a minute per tile, and the memory consumption has grown to 19gb on the editor.
I have noticed that for no reason at all when editing any blue prints while a streaming level is loaded, or editing a streaming map by painting textures on to the landscape, the editor will start off on a reasonable amount of memory and be really quick to respond to commands, but for no reason at all, memory consumption will ramp up to between 16gb to 24gb and that is when the editor becomes virtually unresponsive when saving tiles, editing blueprints, or unloading tiles or painting on to the landscape. It doesn’t seem to be related to the number of tiles as I have similar issues when editing smaller maps.