28 Jul 2026    =====================================
                Concorde, Hexaly, and LKH on TSPLIB
               =====================================
                           Hans Mittelmann
                         <mittelmann@asu.edu>

Logfiles are at: plato.asu.edu/ftp/hex_con_logs/

Platform: AMD Ryzen 9 5900X (12 cores, 128GB). Concorde 03.12.19. Hexaly 15.0, LKH-2.0.11, Random seed for Concorde 99.

Hexaly frequently compares their hybrid heuristic code to exact solvers such as Gurobi and Concorde, see here.

One may rather compare to other heuristics such as LKH in case of the TSP; that also works for asymmetric cases.

This benchmark is showing how well symmetric TSP problems from TSPLIB can be approximately solved in a matter of minutes with the codes.

===============================================================================
geom mean                  88              10                 1
-------------------------------------------------------------------------------
prob         optimum    Hexaly    gap  Concorde    gap       LKH    gap   time
===============================================================================
brd14051     469385     483988   3.11    471013   0.35    469423   0.008   300
d15112      1573084    1598270   1.60   1578568   0.35   1573377   0.02    300
d18512       645238     689073   6.79    647586   0.36    645805$  0.09    300
d2103         80450      80588   0.17     81377   1.15     80494   0.05    600
fl3795        28772      28948   0.61     28782   0.03     28935   0.57    300
fnl4461      182566     185105   1.39    183039   0.26    182566      0     60
pcb3038      137694     139600   1.38    137840   0.11    137694      0    120
pla7397    23260728   23690400   1.85  23394587   0.58  23268800   0.03     60
pr2392       378032     382548   1.19    378032      0    378032      0     60
rl11849      923288     939969   1.81    929094   0.63    923339   0.006   600
rl5915       565530     574471   1.58    566951   0.25    565598   0.01    600
rl5934       556045     567837   2.12    557359   0.24    556172   0.02    600
u2152         64253      64874   0.97     64317   0.10     64253      0     60
u2319        234256     234847   0.25    234256      0    234256      0     60
usa13509   19982859   20575000   2.96  20063669   0.40  19984733   0.009   600
===============================================================================
Optimal and best objective and gaps reached after given time. LKH with single 
run and default parameters. $: time increased to 330s. Scaled and shifted 
geometric mean of gaps.