User Tools

Site Tools


solver:is_it_possible_that_a_concurrent_execution_takes_longer_than_a_non-concurrent_execution_for_the_same_model

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

solver:is_it_possible_that_a_concurrent_execution_takes_longer_than_a_non-concurrent_execution_for_the_same_model [2007/11/20 19:17]
Franz Nelissen created
solver:is_it_possible_that_a_concurrent_execution_takes_longer_than_a_non-concurrent_execution_for_the_same_model [2007/11/20 19:17] (current)
Franz Nelissen
Line 2: Line 2:
  
   - Solving an LP with concurrent is always as fast as solving sequentially with one of the methods run in concurrent mode, but the ''​resusd''​ can be much larger for the concurrent since we report real time in the concurrent and CPU time in the sequential run. Depending on the load of the machine this can be quiet different.   - Solving an LP with concurrent is always as fast as solving sequentially with one of the methods run in concurrent mode, but the ''​resusd''​ can be much larger for the concurrent since we report real time in the concurrent and CPU time in the sequential run. Depending on the load of the machine this can be quiet different.
- 
   - If we talk about parallel MIP (parallel solve of node LPs), then the parallel run can be slower than the sequential, since the parallel can go a different route in the algorithm leading to poorer performance even if the operation are carried out in parallel. The '​deterministic'​ mode is not helping here. It just guarantees that we get the same performance with multiple runs. It can still make a poor decision at the beginning of the B&C tree resulting in poorer performance. We have seen few examples where this happens, but overall parallel pays off nicely.   - If we talk about parallel MIP (parallel solve of node LPs), then the parallel run can be slower than the sequential, since the parallel can go a different route in the algorithm leading to poorer performance even if the operation are carried out in parallel. The '​deterministic'​ mode is not helping here. It just guarantees that we get the same performance with multiple runs. It can still make a poor decision at the beginning of the B&C tree resulting in poorer performance. We have seen few examples where this happens, but overall parallel pays off nicely.
  
IMPRESSUM / LEGAL NOTICEPRIVACY POLICY solver/is_it_possible_that_a_concurrent_execution_takes_longer_than_a_non-concurrent_execution_for_the_same_model.txt ยท Last modified: 2007/11/20 19:17 by Franz Nelissen