After registering for a Student subscription, students have unlimited free Cloud Credits for rendering.
Education renderings are managed in special queue which may become busy during peak periods, such as the end of a semester.
Avoid long waits by:
Some users may have both commercial and education entitlements associated with the same email address. In this situation, when a user runs out of commercial credits, the education credits are used. Depending on server load, this could noticeably delay the rendering.