Sometime I don’t understand, my lightcache is very very low 
, nothing special in the scene.
Is someone know a issue with this?
Is there something (mtl, setting,scale) which could block the LC
Thanks
is the lc file small? or is the level of light low?
Thanks Jack02 for the reply, llightcache is 4.8 Mo.
What do you mean by level of light?
what do you mean by very very low?? the MB (Mo for you :-)) size of the light cache
Or its light level… brightness…
I speak about lightcache prepass. and very slow (for me 
) is near 5 min with 1000 subdiv and a low irmap setting. (to make preview)
In 1000/750pix.
oooooooooooooh. he forgot a s in slow. now the topic makes a heck of alot more sence
humhum…
do you have a lot of displacement?
very bright or white materials can slow it down too because they will cause the rays to bounce a lot more.
no displacement, and I have already checked the pure white mtl.
Does transparency could be the cause of that? I have lot of glass mtl.
quite possibly.
Is it a lot of layered glass? like glass behind glass behind glass?
check the size of your maps.
large textures will cause very slow LC prepass calcs.
You can also try unchecking the Show Calc Phase.