OptiX scene construction suddenly very slow

Question

For some unknown reason, constructing a scene with OptiX suddenly became very slow, even for a trivial scene with 2 triangles. This used to take a few milliseconds, but it now computes for more than 1 second.

What could have happened?

Answer 1

The cache used by OptiX might have grown too large or gotten corrupted in some way. Try deleting it and trying again. On Linux:

rm /var/tmp/OptixCache/cache.db