Problems with Scaling
The main problem with scaling shared memory machines is the memory Latency problem
- The directory schemes we have looked at address the problem of maintaining memory consistency between distributed, shared memory blocks.
- They do not assist in solving the basic problem that if a memory location is far away, it will take a long time to get the contents of the location
- Stanford Dash - 30 clocks, 100 clocks, and 135 clocks
- Communication is KEY to parallel applications, so accessing shared locations that may be far away will be done OFTEN