DAZ character have many materials with many large and detailed textures. Loading all these textures in Blender can cause serious performance problems, because the textures may fill up the available RAM. The situation can be especially critical with Eevee, which can cause the computer to freeze completely. To handle this problem the DAZ Importer has a tool for downsizing textures, cf. previous blog posts here and here. However, this tool is incovenient because it uses Open CV, which is not part of the Blender distribution but most be installed separately.
Fortunately, Alessandro Padovani pointed out that there is another, simpler way to limit textures size: Blender's built-in Simplification feature.
|Simplification turned off. Memory consumption 2019 M, peak 2209 M.|
Here is a render of Aiko with the default settings.
|Texture limit 512. Memory consumption 333M, peak 523M.|
And here is the same scene with simplification turned on. The difference in quality is hardly visible (at least I don't see any), but the memory consumption has been reduced by 80% or so. Quite nice. The render time is not really affected though.
|Textures resized, implification turned off. Memory consumption 377 M, peak 568 M.|
For a more in-depth explaination, see Alessandro's post.