#4741 closed defect (fixed)
analyzeInitialSystem scales as O(N^3) when NF is used
| Reported by: | casella | Owned by: | perost |
|---|---|---|---|
| Priority: | high | Milestone: | 2.0.0 |
| Component: | New Instantiation | Version: | |
| Keywords: | Cc: |
Description
Please consider the ScalableTestSuite.Thermal.Advection.ScaledExperiments.AdvectionReaction_N_XXX models in the ScalableTestSuite.
The times spent by the analyzeInitialSystem function of the back-end when the old FE is used are roughly linear with N and have a marginal impact on the total build time. If you check the times spent when the NF is used, you get these values:
| N | Time (s) |
|---|---|
| 400 | 0.08 |
| 800 | 0.61 |
| 1600 | 4.74 |
| 3200 | 40.50 |
It seems that for some reason if the backend is handed the model by the NF it scales very badly. Please check.
Change History (2)
comment:1 Changed 7 years ago by perost
- Resolution set to fixed
- Status changed from new to closed
comment:2 Changed 7 years ago by casella
Wow. Good that I spotted this as a performance issue :)
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Fixed in 58a87d01. The issue was that the scalarization module accidentally paired type attributes up with the wrong expression. So e.g. Real x[1](start = 0.0, fixed = true) would become Real x[1](start = true, fixed = 0.0) after scalarization, which obviously caused a few issues.