I'm trying to export an image of my project with a size of several hundred megapixels (32768x16384) via the snapshot command and all I get is an output file with 0 KB and no error message. I can export 16384x8192 just fine, but apparently 32768x16384 is too much.
I have 8 GB RAM but according to perfmon.exe QGIS doesn't even use half that when attempting to export the image. A 32768x16384x24 bitmap is still only 1.5 GB in size anyway.
Trying to narrow down the issue I also noticed that there is some other weird stuff going on when exporting images with very large dimensions. I exported the same narrow horizontal strip of a world map both in 16834x1024 and in 65536x4096, and in the larger image everything east of the prime meridian is just missing:
The images above use the global GADM database with a Miller projection (EPSG:53003).
Possibly related to this is a similar issue I have where all raster images (e.g. from Natural Earth) are cut off east of Okinawa. This happens regardless of resolution, but only with some projections. For example, it happens with EPSG:53003 (Sphere_Miller_Cylindrical), EPSG:54003 (World_Miller_Cylindrical), EPSG:54004 (World_Mercator) and EPSG:3395 (WGS 84 / World Mercator) but not with EPSG:4326 (WGS 84).
Edit: I still have these issues with QGIS 2.14.3 Essen and now 24GB RAM; can someone please try to reproduce them on 64-bit Win 7?