List some of the Dis-advantages of Layered Architecture.

Answer:

Low Efficiency
Data transfer occurs through a number of intermediate layers. This is less efficient than a group of objects communicating directly with each other
Granularity of Layers
The decision about the granularity of layers and the assignments of tasks to the layers is difficult. Too few layers do not fully exploit the pattern and too many layers add overheard of data transfer.
Duplication
Work Services performed by lower layers may not be required by higher layers and those performed by higher layers may not be needed by the lower layers. The duplication has a negative impact on the performance of the system