PREMA.CDT3D

Decoupled Approach for CDT3D

1. Take advantage of CDT3D performance and mesh quality capability and create a ‘coarse’ mesh
2. Decompose the mesh into N subdomains (N > P)
3. Distribute and refine each subdomain in parallel with no communication.

Domain Decomposition

Due to the absence of appropriate software simple heuristics have been employed

Preliminary Results (May 2017)

Initial Mesh: 880k Tetrahedra; Final Mesh 150M Tetrahedra ; Number of Subdomains 640

empty	User Handler threads	Total Time	Subdomain Migrations
Pthreads (32)	-	3288	-
PREMA 64 processes, 128 cores without ILB	1	579	0
PREMA 64 processes, 128 cores with ILB.	1	333	123
PREMA 42 processes, 126 cores with ILB.	2	263	215
PREMA 25 processes, 125 cores with ILB.	3	197	136