Problems With BSP
•Though
threads are often very numerous, it is difficult always to have P log P
available
•Other
considerations
•The
network needs to have high bandwidth
(explained in later lecture, but meaning O(n) bisection bandwidth)
•Network
congestion can be magnified when operating at peak
capacity
•Memory contention
requires that a value be fetched from each processor’s
memory at each cycle …what happens when multiple values are in the same
memory unit?
•What are the implications of slow
memories and fast processors?