Standard advice about handling large raster datasets on QGIS (and elsewhere?) usually suggests building a raster pyramid. If I understand correctly this process creates reduced resolution (i.e. resampled rasters with smaller dimensions) copies of the raster images so that when zoomed out the GIS software can display these instead of the full resolution rasters.
When using professionally produced tiled raster mapping datasets, for example rasters from the UK Ordnance Survey for use as basemapping, it is normal to set up a QGIS project to use multiple different raster layers depending on zoom level. The consequence is that when zoomed out a different raster layer is used altogether.
When working in this way is there any gain from producing a raster pyramid, or will this actually be complicating things?
(I'm investigating how to improve performance in the situation described - where we use several VRT files with QGIS, each accessing a tiled raster dataset, some with a large number of tiles. I'm also be struggling with one dataset with so many tiles referenced by the VRT that my PC/QGIS can't cope, even when zoomed in to show only one tile.)