Instance Created:  April 26, 2002
Number of Cities:  2217
Optimal Value:  6764
Solved:  January 11, 2003
Solution Method:  Concorde, QSopt LP solver
Solution Time:  1035677 seconds, UltraSparc III, 900 MHz

History

Date	Gap	Lower Bound	Tour
6.10.02			6765 - Best of 10 runs of LKH, each with n trials. Total running time 2700 seconds on an AMD Althlon 1900+ processor (1.6 GHz).
1.11.03	Optimal	6764 - Concorde (default settings) using QSopt as an LP solver. The run was carried out on a Sun V480 (900 MHz UltraSparc III), in 1035677 seconds, using 2209 nodes in the branch-and-bound-tree.	6764 - Found during the branching run.

Notes

1. Concorde is our linear-programming based TSP solver.

2. linkern is an implementation of Martin, Otto, and Felten's Chained Lin-Kernighan heuristic. It is included in the Concorde code.

3. LKH is Keld Helsgaun's powerful implementation of the Lin-Kernighan heuristic.

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