Yafaray uses disproportionate more RAM for textures that it should.

The checker material in the below attached scene, has 3x 4096x4096 textures applied, as follows:

DIFFUSE: 4096 x 4096 RGB image = 48 MB in memory

BUMP: 4096 x 4096 grayscale image = 16 MB in memory

SPEC: 4096 x 4096 grayscale image = 16 MB in memory

Total in-memory need for textures is: 80 MB

If rendered from the command line the yafaray-xml process uses 876.4 MB of RAM. If the same scene is rendered without the textured material (with the NoTex material applied instead), the Yafaray-xml process uses 87.3 MB. This means that Yafaray has a memory leak ragarding loading textures, as the difference between the two teste is as much as the textures would be loaded 9 times.

The same scene (textured) was tested with Blender internal which uses a more realistic 157 MB and Octane Render which usage is also in line with BI: 153 MB

See this posts for additional details:

http://www.yafaray.org/community/forum/viewtopic.php?p=25277#p25277

http://www.yafaray.org/community/forum/viewtopic.php?p=25299#p25299