Major difference between Linux (cluster) and Windows (computer) with same parameters
AnsweredDear,
I am testing a MIP for an arc flow formulation and the behavior is surprising. I tested all my instances on a cluster (Linux) but it turns that my computer (Windows) is able to solve more instances. For some instances on the cluster, it seems that Gurobi is stuck in the root relaxation. I put the logs below for the same instance that run on my computer and on the cluster, showing major differences although the parameters are the same (same version of Gurobi, same number of threads, same time limit, …).
How can I explain this behavior?
Best regards and thank you for your explanations
Log of the cluster, stuck in the root relaxation :
Gurobi Optimizer version 13.0.0 build v13.0.0rc1 (linux64 - "Rocky Linux 8.7 (Green Obsidian)")
CPU model: AMD EPYC 7542 32-Core Processor, instruction set [SSE2|AVX|AVX2]
Thread count: 64 physical cores, 64 logical processors, using up to 8 threads
Non-default parameters:
TimeLimit 3576.156509
Threads 8
Optimize a model with 52430 rows, 2591209 columns and 7750364 nonzeros (Max)
Model fingerprint: 0xac5196c8
Model has 1 linear objective coefficients
Variable types: 1 continuous, 2591208 integer (0 binary)
Coefficient statistics:
Matrix range [1e+00, 4e+05]
Objective range [1e+00, 1e+00]
Bounds range [0e+00, 0e+00]
RHS range [1e+00, 4e+04]
Found heuristic solution: objective -0.0000000
Presolve removed 17 rows and 13 columns (presolve time = 5s)...
Presolve removed 25 rows and 17 columns (presolve time = 10s)...
Presolve removed 25 rows and 17 columns (presolve time = 15s)...
Presolve removed 25 rows and 21 columns (presolve time = 20s)...
Presolve removed 29 rows and 25 columns (presolve time = 25s)...
Presolve removed 29 rows and 25 columns (presolve time = 30s)...
Presolve removed 29 rows and 25 columns (presolve time = 35s)...
Presolve removed 29 rows and 25 columns
Presolve time: 38.82s
Presolved: 52401 rows, 2591184 columns, 7749483 nonzeros
Variable types: 0 continuous, 2591184 integer (762607 binary)
Deterministic concurrent LP optimizer: primal simplex, dual simplex, and barrier
Showing barrier log only...
Root barrier log...
Ordering time: 3.12s
Barrier statistics:
AA' NZ : 5.173e+06
Factor NZ : 1.827e+07 (roughly 1.2 GB of memory)
Factor Ops : 7.433e+09 (less than 1 second per iteration)
Threads : 6
Objective Residual
Iter Primal Dual Primal Dual Compl Time
0 1.71713418e+08 2.72392337e+07 1.44e+06 1.07e+02 1.79e+04 58s
1 1.00391047e+07 2.27569388e+07 7.88e+04 7.28e-12 9.82e+02 59s
2 1.83295918e+06 8.47256912e+06 9.79e+03 7.28e-12 1.23e+02 60s
3 6.93858425e+05 1.49529354e+06 2.22e+02 7.73e-12 2.95e+00 61s
4 6.74284787e+05 1.12991883e+06 5.06e+01 9.48e-11 7.21e-01 62s
5 6.73038445e+05 1.10579307e+06 4.05e+01 9.09e-11 5.88e-01 63s
6 6.71743689e+05 1.06605671e+06 3.04e+01 1.35e-10 4.52e-01 63s
7 6.70548606e+05 9.82055145e+05 2.17e+01 1.28e-10 3.22e-01 64s
8 6.70434836e+05 9.34268171e+05 2.10e+01 2.76e-10 2.99e-01 65s
9 6.68927942e+05 9.03617329e+05 1.29e+01 6.55e-10 1.95e-01 66s
10 6.63454167e+05 8.85693374e+05 1.01e+01 9.30e-10 1.56e-01 67s
11 6.62952611e+05 8.53777950e+05 8.10e+00 7.35e-10 1.22e-01 69s
12 6.59933147e+05 8.01490019e+05 2.71e+00 6.61e-10 5.23e-02 70s
13 6.58967095e+05 7.27855578e+05 1.65e-01 5.80e-10 1.42e-02 71s
14 6.59661739e+05 6.91847836e+05 3.69e-02 3.90e-10 6.31e-03 73s
15 6.60510214e+05 6.78392469e+05 1.30e-02 4.18e-10 3.47e-03 73s
16 6.61058493e+05 6.74049625e+05 7.73e-03 4.51e-10 2.52e-03 74s
17 6.61435485e+05 6.70579590e+05 5.56e-03 4.63e-10 1.77e-03 75s
18 6.61604825e+05 6.69291442e+05 4.92e-03 5.65e-10 1.49e-03 76s
19 6.61863716e+05 6.68635035e+05 4.10e-03 5.91e-10 1.31e-03 77s
20 6.62383708e+05 6.67065079e+05 2.69e-03 5.10e-10 9.05e-04 77s
21 6.62982805e+05 6.66558108e+05 1.56e-03 6.05e-10 6.91e-04 78s
22 6.63602075e+05 6.65520097e+05 6.66e-04 4.67e-10 3.71e-04 80s
23 6.64384902e+05 6.64567320e+05 1.95e-05 4.27e-10 3.52e-05 81s
24 6.64477688e+05 6.64511416e+05 4.89e-06 3.48e-10 6.51e-06 82s
25 6.64236678e+05 6.64499260e+05 3.26e-04 4.11e-10 5.12e-05 83s
26 6.64466906e+05 6.64497507e+05 3.99e-05 3.85e-10 5.98e-06 83s
27 6.64482316e+05 6.64490848e+05 1.68e-04 2.69e-10 2.28e-06 84s
28 6.64486935e+05 6.64485235e+05 1.41e-04 2.76e-10 1.18e-07 85s
29 6.64485132e+05 6.64485208e+05 2.38e-06 4.06e-10 1.41e-11 86s
30 6.64485315e+05 6.64485208e+05 1.65e-06 3.97e-10 1.61e-12 87s
Barrier solved model in 30 iterations and 86.70 seconds (62.62 work units)
Optimal objective 6.64485315e+05
Root crossover log...
41228 DPushes remaining with DInf 0.0000000e+00 87s
0 DPushes remaining with DInf 0.0000000e+00 90s
913114 PPushes remaining with PInf 1.2723630e+03 90s
911229 PPushes remaining with PInf 1.2522091e+03 90s
863368 PPushes remaining with PInf 1.2089998e+03 95s
830439 PPushes remaining with PInf 1.1947495e+03 100s
802202 PPushes remaining with PInf 1.1899223e+03 105s
773665 PPushes remaining with PInf 1.1872209e+03 110s
744527 PPushes remaining with PInf 1.1720164e+03 115s
720731 PPushes remaining with PInf 1.1569351e+03 120s
696003 PPushes remaining with PInf 1.1545073e+03 125s
669130 PPushes remaining with PInf 1.1512253e+03 130s
641704 PPushes remaining with PInf 1.1469379e+03 135s
601674 PPushes remaining with PInf 9.8570606e+02 140s
572214 PPushes remaining with PInf 9.5835884e+02 145s
538025 PPushes remaining with PInf 9.3146051e+02 150s
508316 PPushes remaining with PInf 9.0867860e+02 155s
473737 PPushes remaining with PInf 8.7358913e+02 160s
426880 PPushes remaining with PInf 8.0792493e+02 165s
398857 PPushes remaining with PInf 7.5863491e+02 170s
367062 PPushes remaining with PInf 7.3047078e+02 175s
334967 PPushes remaining with PInf 7.1074237e+02 180s
304526 PPushes remaining with PInf 6.9484186e+02 185s
277895 PPushes remaining with PInf 6.8218753e+02 190s
251554 PPushes remaining with PInf 6.6702676e+02 195s
223958 PPushes remaining with PInf 6.3523675e+02 200s
199104 PPushes remaining with PInf 6.1257309e+02 205s
173020 PPushes remaining with PInf 5.7202930e+02 210s
146140 PPushes remaining with PInf 5.4253225e+02 215s
119782 PPushes remaining with PInf 5.0083615e+02 220s
91437 PPushes remaining with PInf 4.7660120e+02 225s
57688 PPushes remaining with PInf 4.3731244e+02 230s
21281 PPushes remaining with PInf 4.1322065e+02 235s
0 PPushes remaining with PInf 3.7635916e+02 238s
Push phase complete: Pinf 3.7635916e+02, Dinf 4.1848068e-08 238s
Root simplex log...
Iteration Objective Primal Inf. Dual Inf. Time
954345 6.6448521e+05 0.000000e+00 1.004431e-06 238s
954725 6.6448521e+05 3.846646e+04 0.000000e+00 241s
955283 6.6448521e+05 3.578668e+04 0.000000e+00 245s
955874 6.6448521e+05 1.682234e+04 0.000000e+00 251s
956094 6.6448521e+05 5.048414e+04 0.000000e+00 256s
956530 6.6448521e+05 3.842797e+04 0.000000e+00 261s
956893 6.6448521e+05 1.142103e+04 0.000000e+00 266s
957326 6.6448520e+05 1.014498e+04 0.000000e+00 272s
957446 6.6448520e+05 2.270423e+04 0.000000e+00 276s
957716 6.6448520e+05 2.409109e+04 0.000000e+00 286s
957826 6.6448520e+05 3.774038e+04 0.000000e+00 295s
957936 6.6448520e+05 2.381443e+04 0.000000e+00 301s
958236 6.6448520e+05 1.138421e+04 0.000000e+00 307s
958426 6.6448520e+05 1.143006e+04 0.000000e+00 312s
958556 6.6448520e+05 6.154686e+03 0.000000e+00 316s
958856 6.6448520e+05 1.556142e+04 0.000000e+00 321s
959342 6.6448520e+05 9.444888e+03 0.000000e+00 325s
959645 6.6448520e+05 1.230790e+04 0.000000e+00 330s
959888 6.6448520e+05 7.113063e+03 0.000000e+00 335s
960088 6.6448520e+05 1.010527e+04 0.000000e+00 341s
960198 6.6448520e+05 5.523266e+03 0.000000e+00 346s
960298 6.6448520e+05 1.063948e+04 0.000000e+00 358s
960398 6.6448520e+05 8.998705e+03 0.000000e+00 373s
960518 6.6448520e+05 1.398491e+04 0.000000e+00 378s
960618 6.6448520e+05 1.411681e+04 0.000000e+00 386s
960718 6.6448520e+05 1.139570e+04 0.000000e+00 396s
960838 6.6448520e+05 7.910337e+03 0.000000e+00 403s
960928 6.6448520e+05 4.328696e+03 0.000000e+00 408s
961294 6.6448520e+05 4.596173e+03 0.000000e+00 417s
961394 6.6448520e+05 1.053125e+04 0.000000e+00 430s
961494 6.6448520e+05 9.031781e+03 0.000000e+00 440s
961594 6.6448520e+05 7.504791e+03 0.000000e+00 453s
961674 6.6448520e+05 7.770398e+03 0.000000e+00 460s
961904 6.6448520e+05 9.742624e+03 0.000000e+00 468s
962004 6.6448520e+05 7.008253e+03 0.000000e+00 478s
962114 6.6448520e+05 7.491072e+03 0.000000e+00 484s
962214 6.6448520e+05 1.054076e+04 0.000000e+00 488s
962314 6.6448519e+05 8.371170e+03 0.000000e+00 501s
962414 6.6448519e+05 1.755043e+04 0.000000e+00 507s
962624 6.6448519e+05 1.041356e+04 0.000000e+00 512s
962714 6.6448519e+05 1.696977e+04 0.000000e+00 521s
962814 6.6448519e+05 1.415358e+04 0.000000e+00 529s
962914 6.6448519e+05 5.408976e+03 0.000000e+00 533s
963134 6.6448519e+05 2.213765e+04 0.000000e+00 536s
963284 6.6448519e+05 2.346250e+04 0.000000e+00 541s
963680 6.6448519e+05 1.077798e+04 0.000000e+00 546s
963970 6.6448519e+05 3.476788e+04 0.000000e+00 553s
964280 6.6448518e+05 1.084789e+04 0.000000e+00 559s
964390 6.6448518e+05 3.615979e+04 0.000000e+00 564s
964490 6.6448518e+05 6.948379e+03 0.000000e+00 568s
964610 6.6448518e+05 8.270124e+03 0.000000e+00 573s
964710 6.6448518e+05 2.521262e+04 0.000000e+00 583s
964810 6.6448518e+05 1.675628e+04 0.000000e+00 590s
964910 6.6448518e+05 3.627353e+03 0.000000e+00 605s
965020 6.6448518e+05 4.642129e+03 0.000000e+00 616s
965260 6.6448518e+05 5.697669e+03 0.000000e+00 626s
965400 6.6448518e+05 1.533641e+04 0.000000e+00 635s
965500 6.6448518e+05 5.936073e+03 0.000000e+00 642s
965610 6.6448518e+05 5.057990e+03 0.000000e+00 655s
965710 6.6448518e+05 7.199624e+03 0.000000e+00 659s
965840 6.6448518e+05 7.861170e+03 0.000000e+00 671s
965970 6.6448518e+05 1.847465e+03 0.000000e+00 681s
966416 6.6448518e+05 2.327861e+03 0.000000e+00 686s
966656 6.6448518e+05 2.893274e+03 0.000000e+00 693s
966756 6.6448518e+05 4.518069e+03 0.000000e+00 701s
966886 6.6448518e+05 4.750486e+03 0.000000e+00 712s
967036 6.6448518e+05 1.029202e+04 0.000000e+00 724s
967146 6.6448518e+05 7.715165e+03 0.000000e+00 727s
967369 6.6448518e+05 4.260339e+03 0.000000e+00 731s
967752 6.6448518e+05 4.353307e+03 0.000000e+00 737s
968095 6.6448517e+05 7.355083e+03 0.000000e+00 741s
968205 6.6448517e+05 1.467489e+04 0.000000e+00 751s
968385 6.6448517e+05 1.087511e+04 0.000000e+00 760s
968505 6.6448517e+05 6.017316e+03 0.000000e+00 770s
968665 6.6448517e+05 3.424625e+03 0.000000e+00 775s
969101 6.6448517e+05 3.702549e+03 0.000000e+00 781s
969414 6.6448517e+05 2.599440e+03 0.000000e+00 789s
969730 6.6448517e+05 4.402257e+03 0.000000e+00 791s
969980 6.6448517e+05 7.071508e+03 0.000000e+00 798s
970080 6.6448517e+05 6.165309e+03 0.000000e+00 809s
970180 6.6448517e+05 1.524923e+04 0.000000e+00 819s
970290 6.6448517e+05 5.024800e+03 0.000000e+00 831s
970400 6.6448517e+05 6.502941e+03 0.000000e+00 843s
970500 6.6448517e+05 7.874346e+03 0.000000e+00 854s
970600 6.6448517e+05 6.281191e+03 0.000000e+00 861s
970720 6.6448517e+05 9.747963e+03 0.000000e+00 870s
970820 6.6448517e+05 4.800299e+03 0.000000e+00 879s
970920 6.6448516e+05 4.627273e+03 0.000000e+00 887s
971030 6.6448516e+05 1.209643e+04 0.000000e+00 898s
971140 6.6448516e+05 1.456569e+04 0.000000e+00 911s
971240 6.6448516e+05 1.035649e+04 0.000000e+00 920s
971340 6.6448516e+05 1.049092e+04 0.000000e+00 930s
971450 6.6448516e+05 1.086769e+04 0.000000e+00 938s
971530 6.6448516e+05 3.258917e+03 0.000000e+00 942s
971740 6.6448516e+05 2.132189e+04 0.000000e+00 946s
971910 6.6448516e+05 5.750415e+03 0.000000e+00 951s
972110 6.6448516e+05 5.956297e+03 0.000000e+00 957s
972210 6.6448516e+05 1.450823e+04 0.000000e+00 966s
972320 6.6448516e+05 2.183092e+04 0.000000e+00 981s
972420 6.6448516e+05 1.658738e+04 0.000000e+00 988s
972520 6.6448516e+05 1.535780e+04 0.000000e+00 1001s
972710 6.6448516e+05 2.705992e+04 0.000000e+00 1007s
972810 6.6448516e+05 3.768714e+04 0.000000e+00 1022s
972910 6.6448516e+05 5.783456e+03 0.000000e+00 1036s
973010 6.6448516e+05 1.213646e+04 0.000000e+00 1051s
973120 6.6448516e+05 1.684178e+04 0.000000e+00 1057s
973240 6.6448515e+05 1.049671e+04 0.000000e+00 1072s
973340 6.6448515e+05 1.325765e+04 0.000000e+00 1084s
973440 6.6448515e+05 3.488714e+04 0.000000e+00 1097s
973540 6.6448515e+05 2.239639e+04 0.000000e+00 1102s
973640 6.6448515e+05 7.457060e+03 0.000000e+00 1111s
973740 6.6448515e+05 2.617823e+04 0.000000e+00 1123s
973850 6.6448515e+05 1.747792e+04 0.000000e+00 1136s
973950 6.6448515e+05 7.708516e+03 0.000000e+00 1144s
974050 6.6448515e+05 6.128171e+03 0.000000e+00 1155s
974150 6.6448515e+05 3.592951e+03 0.000000e+00 1166s
974250 6.6448515e+05 1.095093e+04 0.000000e+00 1178s
974350 6.6448515e+05 2.052343e+04 0.000000e+00 1187s
974450 6.6448515e+05 1.503507e+04 0.000000e+00 1199s
974550 6.6448515e+05 7.974727e+03 0.000000e+00 1211s
974650 6.6448515e+05 1.211836e+04 0.000000e+00 1217s
974860 6.6448515e+05 1.347996e+04 0.000000e+00 1233s
974960 6.6448515e+05 3.681465e+03 0.000000e+00 1241s
975060 6.6448515e+05 1.107258e+04 0.000000e+00 1251s
975150 6.6448515e+05 3.938738e+03 0.000000e+00 1259s
975240 6.6448515e+05 3.778872e+03 0.000000e+00 1262s
975340 6.6448515e+05 3.824136e+03 0.000000e+00 1265s
975640 6.6448514e+05 8.681908e+03 0.000000e+00 1273s
975740 6.6448514e+05 9.843129e+03 0.000000e+00 1275s
975910 6.6448514e+05 6.964286e+03 0.000000e+00 1280s
976170 6.6448514e+05 1.082910e+04 0.000000e+00 1285s
976320 6.6448514e+05 2.384654e+04 0.000000e+00 1291s
976540 6.6448514e+05 5.748658e+03 0.000000e+00 1297s
976810 6.6448514e+05 3.703030e+04 0.000000e+00 1302s
976910 6.6448514e+05 4.101963e+03 0.000000e+00 1305s
977250 6.6448513e+05 1.565991e+04 0.000000e+00 1313s
977330 6.6448513e+05 3.647090e+03 0.000000e+00 1316s
977420 6.6448513e+05 5.128617e+03 0.000000e+00 1322s
977520 6.6448513e+05 4.525806e+03 0.000000e+00 1330s
977620 6.6448513e+05 1.873244e+03 0.000000e+00 1337s
977720 6.6448513e+05 1.763409e+03 0.000000e+00 1345s
977820 6.6448513e+05 1.620666e+03 0.000000e+00 1353s
977930 6.6448513e+05 5.510151e+03 0.000000e+00 1362s
978030 6.6448513e+05 7.513816e+03 0.000000e+00 1371s
978140 6.6448513e+05 4.753209e+03 0.000000e+00 1381s
978240 6.6448513e+05 1.071751e+04 0.000000e+00 1390s
978340 6.6448513e+05 6.669004e+03 0.000000e+00 1400s
978440 6.6448513e+05 2.821500e+04 0.000000e+00 1411s
978540 6.6448513e+05 5.604026e+03 0.000000e+00 1420s
978733 6.6448513e+05 2.526427e+03 0.000000e+00 1425s
978863 6.6448512e+05 2.146615e+03 0.000000e+00 1431s
978963 6.6448512e+05 7.536291e+03 0.000000e+00 1441s
979073 6.6448512e+05 7.538699e+03 0.000000e+00 1450s
979183 6.6448512e+05 3.488701e+03 0.000000e+00 1456s
979293 6.6448512e+05 5.521220e+03 0.000000e+00 1462s
979393 6.6448512e+05 6.710781e+03 0.000000e+00 1469s
979493 6.6448512e+05 6.880382e+03 0.000000e+00 1475s
979603 6.6448512e+05 4.357771e+03 0.000000e+00 1485s
979703 6.6448512e+05 4.799942e+03 0.000000e+00 1489s
979803 6.6448512e+05 6.773395e+03 0.000000e+00 1499s
979903 6.6448512e+05 2.644506e+03 0.000000e+00 1509s
980003 6.6448512e+05 2.838682e+03 0.000000e+00 1519s
980113 6.6448512e+05 1.070051e+03 0.000000e+00 1530s
980213 6.6448512e+05 1.171984e+03 0.000000e+00 1540s
980353 6.6448512e+05 1.199388e+03 0.000000e+00 1551s
980463 6.6448512e+05 2.082902e+03 0.000000e+00 1559s
980563 6.6448512e+05 6.888466e+03 0.000000e+00 1570s
980663 6.6448512e+05 1.611465e+03 0.000000e+00 1580s
980763 6.6448512e+05 2.382791e+03 0.000000e+00 1591s
980873 6.6448512e+05 1.878579e+03 0.000000e+00 1602s
980973 6.6448512e+05 2.914389e+03 0.000000e+00 1613s
981073 6.6448512e+05 1.368926e+03 0.000000e+00 1625s
981173 6.6448512e+05 2.964766e+03 0.000000e+00 1638s
981273 6.6448512e+05 4.315816e+03 0.000000e+00 1650s
981383 6.6448512e+05 3.040748e+03 0.000000e+00 1662s
981503 6.6448512e+05 9.464487e+02 0.000000e+00 1676s
981603 6.6448512e+05 7.104096e+02 0.000000e+00 1689s
981703 6.6448512e+05 1.257036e+03 0.000000e+00 1701s
981803 6.6448512e+05 4.011029e+03 0.000000e+00 1714s
981903 6.6448512e+05 1.162811e+03 0.000000e+00 1726s
982003 6.6448511e+05 1.866267e+03 0.000000e+00 1738s
982103 6.6448511e+05 2.819493e+03 0.000000e+00 1751s
982203 6.6448511e+05 1.888081e+03 0.000000e+00 1763s
982303 6.6448511e+05 1.823623e+03 0.000000e+00 1776s
982403 6.6448511e+05 1.286365e+03 0.000000e+00 1788s
982503 6.6448511e+05 8.753658e+02 0.000000e+00 1800s
982603 6.6448511e+05 7.300443e+02 0.000000e+00 1813s
982703 6.6448511e+05 7.277267e+02 0.000000e+00 1825s
982803 6.6448511e+05 5.696413e+02 0.000000e+00 1838s
982903 6.6448511e+05 2.407835e+03 0.000000e+00 1851s
983003 6.6448511e+05 9.444855e+02 0.000000e+00 1863s
983103 6.6448511e+05 1.758740e+03 0.000000e+00 1875s
983203 6.6448511e+05 1.702819e+03 0.000000e+00 1888s
983303 6.6448511e+05 2.098892e+03 0.000000e+00 1900s
983403 6.6448511e+05 6.113141e+02 0.000000e+00 1912s
983503 6.6448511e+05 1.352264e+03 0.000000e+00 1924s
983603 6.6448511e+05 6.499563e+02 0.000000e+00 1936s
983703 6.6448511e+05 1.123456e+03 0.000000e+00 1949s
983803 6.6448511e+05 1.790675e+03 0.000000e+00 1961s
983903 6.6448511e+05 6.440114e+02 0.000000e+00 1974s
984003 6.6448511e+05 1.020742e+03 0.000000e+00 1986s
984103 6.6448511e+05 1.653699e+03 0.000000e+00 1999s
984213 6.6448511e+05 8.100969e+02 0.000000e+00 2011s
984313 6.6448511e+05 7.929059e+02 0.000000e+00 2023s
984413 6.6448511e+05 1.353186e+03 0.000000e+00 2035s
984513 6.6448511e+05 1.761051e+03 0.000000e+00 2048s
984613 6.6448511e+05 3.415646e+03 0.000000e+00 2059s
984713 6.6448511e+05 2.915748e+03 0.000000e+00 2072s
984813 6.6448511e+05 1.506364e+03 0.000000e+00 2085s
984913 6.6448511e+05 6.189644e+02 0.000000e+00 2097s
985013 6.6448511e+05 8.223176e+02 0.000000e+00 2110s
985113 6.6448511e+05 1.126612e+03 0.000000e+00 2122s
985213 6.6448511e+05 1.444901e+03 0.000000e+00 2135s
985313 6.6448511e+05 6.300421e+02 0.000000e+00 2147s
985413 6.6448511e+05 1.575652e+03 0.000000e+00 2160s
985513 6.6448511e+05 5.000446e+03 0.000000e+00 2172s
985613 6.6448511e+05 1.948708e+03 0.000000e+00 2185s
985753 6.6448511e+05 5.245795e+02 0.000000e+00 2192s
985853 6.6448511e+05 9.095962e+02 0.000000e+00 2201s
985953 6.6448511e+05 7.265646e+02 0.000000e+00 2214s
986053 6.6448511e+05 2.226395e+03 0.000000e+00 2226s
986153 6.6448511e+05 1.387437e+03 0.000000e+00 2239s
986253 6.6448511e+05 1.150127e+03 0.000000e+00 2251s
986353 6.6448511e+05 9.318287e+02 0.000000e+00 2264s
986453 6.6448511e+05 1.487087e+03 0.000000e+00 2276s
986553 6.6448511e+05 5.265718e+02 0.000000e+00 2289s
986653 6.6448511e+05 4.518546e+02 0.000000e+00 2301s
986753 6.6448511e+05 1.789436e+03 0.000000e+00 2314s
986853 6.6448511e+05 8.062875e+03 0.000000e+00 2326s
986953 6.6448511e+05 6.904238e+02 0.000000e+00 2339s
987053 6.6448511e+05 1.109923e+03 0.000000e+00 2351s
987143 6.6448511e+05 3.206967e+03 0.000000e+00 2361s
987233 6.6448511e+05 1.075629e+03 0.000000e+00 2368s
987333 6.6448511e+05 7.592810e+02 0.000000e+00 2375s
987433 6.6448511e+05 5.468260e+02 0.000000e+00 2387s
987533 6.6448511e+05 9.926685e+02 0.000000e+00 2399s
987633 6.6448511e+05 1.834632e+03 0.000000e+00 2410s
987733 6.6448511e+05 2.634964e+03 0.000000e+00 2421s
987833 6.6448511e+05 8.035259e+02 0.000000e+00 2432s
987933 6.6448511e+05 1.451945e+03 0.000000e+00 2443s
988033 6.6448511e+05 1.010956e+03 0.000000e+00 2454s
988133 6.6448511e+05 3.619084e+03 0.000000e+00 2465s
988233 6.6448511e+05 2.717967e+03 0.000000e+00 2476s
988333 6.6448511e+05 8.932612e+02 0.000000e+00 2487s
988433 6.6448511e+05 2.310598e+03 0.000000e+00 2498s
988533 6.6448511e+05 6.562110e+02 0.000000e+00 2509s
988633 6.6448511e+05 8.076149e+02 0.000000e+00 2521s
988733 6.6448511e+05 9.589663e+02 0.000000e+00 2532s
988833 6.6448511e+05 6.154665e+03 0.000000e+00 2543s
988933 6.6448511e+05 6.218734e+03 0.000000e+00 2555s
989033 6.6448511e+05 1.315641e+03 0.000000e+00 2566s
989133 6.6448511e+05 1.969472e+03 0.000000e+00 2577s
989233 6.6448511e+05 4.398937e+02 0.000000e+00 2589s
989333 6.6448511e+05 1.444593e+03 0.000000e+00 2602s
989433 6.6448511e+05 1.718268e+03 0.000000e+00 2614s
989533 6.6448511e+05 5.854307e+02 0.000000e+00 2625s
989633 6.6448511e+05 6.261152e+02 0.000000e+00 2637s
989733 6.6448511e+05 8.314840e+02 0.000000e+00 2649s
989833 6.6448511e+05 1.391061e+03 0.000000e+00 2660s
989933 6.6448511e+05 1.283940e+03 0.000000e+00 2672s
990033 6.6448511e+05 1.069971e+03 0.000000e+00 2684s
990133 6.6448511e+05 1.274034e+03 0.000000e+00 2696s
990233 6.6448511e+05 2.231614e+02 0.000000e+00 2708s
990333 6.6448511e+05 1.434932e+03 0.000000e+00 2720s
990433 6.6448511e+05 9.558272e+02 0.000000e+00 2732s
990533 6.6448511e+05 8.786130e+02 0.000000e+00 2744s
990633 6.6448511e+05 1.747288e+03 0.000000e+00 2756s
990733 6.6448511e+05 4.261203e+03 0.000000e+00 2767s
990833 6.6448511e+05 2.545120e+03 0.000000e+00 2779s
990933 6.6448511e+05 2.689408e+02 0.000000e+00 2791s
991033 6.6448511e+05 1.938459e+03 0.000000e+00 2803s
991133 6.6448511e+05 5.383639e+02 0.000000e+00 2815s
991233 6.6448511e+05 6.440685e+02 0.000000e+00 2827s
991333 6.6448511e+05 5.275504e+02 0.000000e+00 2839s
991433 6.6448511e+05 2.472638e+03 0.000000e+00 2850s
991533 6.6448511e+05 3.966373e+02 0.000000e+00 2862s
991633 6.6448511e+05 3.210104e+03 0.000000e+00 2874s
991733 6.6448511e+05 7.362489e+02 0.000000e+00 2886s
991833 6.6448511e+05 3.150573e+02 0.000000e+00 2898s
991933 6.6448511e+05 4.939645e+02 0.000000e+00 2909s
992013 6.6448511e+05 5.012840e+02 0.000000e+00 2916s
992093 6.6448511e+05 6.986451e+02 0.000000e+00 2923s
992193 6.6448511e+05 1.058803e+03 0.000000e+00 2933s
992293 6.6448511e+05 7.236304e+02 0.000000e+00 2945s
992393 6.6448511e+05 2.767938e+03 0.000000e+00 2956s
992493 6.6448511e+05 4.510819e+02 0.000000e+00 2968s
992593 6.6448511e+05 2.013803e+02 0.000000e+00 2980s
992693 6.6448511e+05 3.673847e+02 0.000000e+00 2991s
992793 6.6448511e+05 5.636450e+02 0.000000e+00 3003s
992893 6.6448511e+05 3.482754e+02 0.000000e+00 3014s
992993 6.6448511e+05 2.884140e+02 0.000000e+00 3026s
993093 6.6448511e+05 6.044275e+02 0.000000e+00 3037s
993193 6.6448511e+05 3.132283e+02 0.000000e+00 3049s
993293 6.6448510e+05 2.606411e+03 0.000000e+00 3061s
993393 6.6448510e+05 5.129666e+02 0.000000e+00 3073s
993493 6.6448510e+05 2.904737e+02 0.000000e+00 3085s
993593 6.6448510e+05 3.240832e+02 0.000000e+00 3098s
993693 6.6448510e+05 3.326950e+02 0.000000e+00 3111s
993793 6.6448510e+05 6.506828e+02 0.000000e+00 3124s
993893 6.6448510e+05 7.940781e+02 0.000000e+00 3137s
993993 6.6448510e+05 4.744870e+02 0.000000e+00 3150s
994093 6.6448510e+05 5.458586e+02 0.000000e+00 3163s
994193 6.6448510e+05 8.421080e+02 0.000000e+00 3176s
994293 6.6448510e+05 2.539152e+02 0.000000e+00 3189s
994393 6.6448510e+05 7.474551e+02 0.000000e+00 3202s
994493 6.6448510e+05 1.654363e+02 0.000000e+00 3215s
994593 6.6448510e+05 8.226154e+02 0.000000e+00 3228s
994693 6.6448510e+05 7.854911e+02 0.000000e+00 3241s
994793 6.6448510e+05 3.658468e+02 0.000000e+00 3254s
994893 6.6448510e+05 1.508401e+03 0.000000e+00 3267s
994993 6.6448510e+05 1.388253e+03 0.000000e+00 3280s
995093 6.6448510e+05 4.632681e+02 0.000000e+00 3293s
995193 6.6448510e+05 1.105620e+03 0.000000e+00 3306s
995293 6.6448510e+05 3.921003e+02 0.000000e+00 3319s
995393 6.6448510e+05 6.061416e+02 0.000000e+00 3332s
995493 6.6448510e+05 9.194720e+02 0.000000e+00 3346s
995686 6.6448510e+05 2.571338e+02 0.000000e+00 3355s
996195 6.6448510e+05 4.583396e+02 0.000000e+00 3362s
996295 6.6448510e+05 7.362682e+02 0.000000e+00 3375s
996395 6.6448510e+05 4.722236e+02 0.000000e+00 3388s
996495 6.6448510e+05 5.712454e+02 0.000000e+00 3401s
996595 6.6448510e+05 2.560261e+02 0.000000e+00 3414s
996695 6.6448510e+05 2.795340e+02 0.000000e+00 3428s
996795 6.6448510e+05 9.443340e+01 0.000000e+00 3441s
996895 6.6448510e+05 1.248812e+02 0.000000e+00 3454s
996995 6.6448510e+05 1.905651e+02 0.000000e+00 3467s
997095 6.6448510e+05 1.843568e+02 0.000000e+00 3480s
997195 6.6448510e+05 1.184414e+02 0.000000e+00 3492s
997295 6.6448510e+05 1.693153e+02 0.000000e+00 3504s
997395 6.6448510e+05 1.066334e+02 0.000000e+00 3516s
997495 6.6448510e+05 9.935722e+01 0.000000e+00 3528s
997595 6.6448510e+05 6.884874e+02 0.000000e+00 3541s
997695 6.6448510e+05 2.943224e+02 0.000000e+00 3553s
997795 6.6448510e+05 1.100804e+03 0.000000e+00 3565s
Crossover time: 3489.41 seconds (2265.50 work units)
Crossover changed status from Optimal to Time Limit
Root relaxation: time limit, 80779 iterations, 3535.11 seconds (2226.62 work units)
Nodes | Current Node | Objective Bounds | Work
Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time
0 0 - 0 -0.00000 1.0889e+08 - - 3576s
Explored 1 nodes (80779 simplex iterations) in 3576.35 seconds (2262.82 work units)
Thread count was 8 (of 64 available processors)
Solution count 1: -0
Time limit reached
Best objective -0.000000000000e+00, best bound 1.088890000000e+08, gap -
User-callback calls 11540, time in user-callback 0.05 sec
Logs of my computer, able to find a very good solution in 948s:
Gurobi Optimizer version 13.0.0 build v13.0.0rc1 (win64 - Windows 11+.0 (26200.2))
CPU model: AMD Ryzen 5 PRO 5675U with Radeon Graphics, instruction set [SSE2|AVX|AVX2]
Thread count: 6 physical cores, 12 logical processors, using up to 8 threads
Non-default parameters:
TimeLimit 3580.441534
Threads 8
Optimize a model with 52430 rows, 2591209 columns and 7750364 nonzeros (Max)
Model fingerprint: 0xac5196c8
Model has 1 linear objective coefficients
Variable types: 1 continuous, 2591208 integer (0 binary)
Coefficient statistics:
Matrix range [1e+00, 4e+05]
Objective range [1e+00, 1e+00]
Bounds range [0e+00, 0e+00]
RHS range [1e+00, 4e+04]
Found heuristic solution: objective -0.0000000
Presolve removed 17 rows and 13 columns (presolve time = 5s)...
Presolve removed 25 rows and 17 columns (presolve time = 11s)...
Presolve removed 25 rows and 17 columns (presolve time = 15s)...
Presolve removed 25 rows and 17 columns (presolve time = 20s)...
Presolve removed 25 rows and 21 columns (presolve time = 25s)...
Presolve removed 29 rows and 25 columns (presolve time = 31s)...
Presolve removed 29 rows and 25 columns (presolve time = 35s)...
Presolve removed 29 rows and 25 columns (presolve time = 40s)...
Presolve removed 29 rows and 25 columns (presolve time = 45s)...
Presolve removed 29 rows and 25 columns (presolve time = 51s)...
Presolve removed 29 rows and 25 columns
Presolve time: 54.09s
Presolved: 52401 rows, 2591184 columns, 7749483 nonzeros
Variable types: 0 continuous, 2591184 integer (762607 binary)
Deterministic concurrent LP optimizer: primal simplex, dual simplex, and barrier
Showing barrier log only...
Root barrier log...
Elapsed ordering time = 5s
Ordering time: 6.68s
Barrier statistics:
AA' NZ : 5.173e+06
Factor NZ : 1.827e+07 (roughly 1.2 GB of memory)
Factor Ops : 7.433e+09 (less than 1 second per iteration)
Threads : 6
Objective Residual
Iter Primal Dual Primal Dual Compl Time
0 1.71713418e+08 2.72392337e+07 1.44e+06 1.07e+02 1.79e+04 85s
1 1.00391047e+07 2.27569388e+07 7.88e+04 5.23e-12 9.82e+02 87s
2 1.83295918e+06 8.47256912e+06 9.79e+03 7.73e-12 1.23e+02 89s
3 6.93858425e+05 1.49529354e+06 2.22e+02 8.30e-12 2.95e+00 92s
4 6.74284787e+05 1.12991883e+06 5.06e+01 8.89e-11 7.21e-01 95s
5 6.73038445e+05 1.10579307e+06 4.05e+01 9.57e-11 5.88e-01 97s
6 6.71743689e+05 1.06605671e+06 3.04e+01 1.38e-10 4.52e-01 98s
7 6.70548606e+05 9.82055145e+05 2.17e+01 1.33e-10 3.22e-01 100s
8 6.70434836e+05 9.34268171e+05 2.10e+01 2.66e-10 2.99e-01 102s
9 6.68927939e+05 9.03617316e+05 1.29e+01 6.19e-10 1.95e-01 104s
10 6.63454168e+05 8.85693374e+05 1.01e+01 8.94e-10 1.56e-01 107s
11 6.62952613e+05 8.53777944e+05 8.10e+00 7.75e-10 1.22e-01 110s
12 6.59933171e+05 8.01490057e+05 2.71e+00 7.18e-10 5.23e-02 113s
13 6.58967094e+05 7.27856352e+05 1.65e-01 4.66e-10 1.42e-02 117s
14 6.59661737e+05 6.91847934e+05 3.69e-02 4.12e-10 6.31e-03 119s
15 6.60510212e+05 6.78392462e+05 1.30e-02 3.66e-10 3.47e-03 122s
16 6.61058483e+05 6.74049749e+05 7.73e-03 4.26e-10 2.52e-03 124s
17 6.61435486e+05 6.70581034e+05 5.56e-03 4.71e-10 1.77e-03 126s
18 6.61604772e+05 6.69288386e+05 4.92e-03 5.43e-10 1.49e-03 127s
19 6.61864110e+05 6.68633691e+05 4.10e-03 5.83e-10 1.31e-03 129s
20 6.62384056e+05 6.67064843e+05 2.69e-03 5.90e-10 9.05e-04 131s
21 6.63045520e+05 6.66559122e+05 1.44e-03 5.82e-10 6.79e-04 134s
22 6.63637004e+05 6.65411574e+05 6.91e-04 4.62e-10 3.43e-04 136s
23 6.64404665e+05 6.64551202e+05 2.02e-05 3.58e-10 2.83e-05 139s
24 6.64477557e+05 6.64511086e+05 6.12e-06 3.95e-10 6.47e-06 141s
25 6.64262407e+05 6.64499359e+05 7.62e-05 4.64e-10 4.60e-05 143s
26 6.64479361e+05 6.64497447e+05 1.23e-05 3.70e-10 3.50e-06 145s
27 6.64472591e+05 6.64486546e+05 9.51e-05 3.61e-10 7.49e-07 147s
28 6.64486759e+05 6.64485218e+05 2.41e-05 2.59e-10 8.23e-09 149s
29 6.64485083e+05 6.64485208e+05 1.25e-05 3.47e-10 3.48e-13 151s
30 6.64485234e+05 6.64485208e+05 1.13e-07 3.92e-10 7.11e-14 153s
Barrier solved model in 30 iterations and 152.73 seconds (62.62 work units)
Optimal objective 6.64485234e+05
Root crossover log...
41192 DPushes remaining with DInf 0.0000000e+00 154s
4698 DPushes remaining with DInf 0.0000000e+00 156s
0 DPushes remaining with DInf 0.0000000e+00 160s
1193881 PPushes remaining with PInf 9.7754199e-06 160s
1174937 PPushes remaining with PInf 3.2682698e-02 165s
1152635 PPushes remaining with PInf 8.0586982e-02 170s
1128991 PPushes remaining with PInf 7.3459147e-02 175s
1104470 PPushes remaining with PInf 5.8931190e-02 180s
1089453 PPushes remaining with PInf 5.2123916e-02 185s
1074076 PPushes remaining with PInf 4.4348081e-02 190s
1059914 PPushes remaining with PInf 3.5366347e-02 195s
1046964 PPushes remaining with PInf 4.0489674e-02 200s
1034310 PPushes remaining with PInf 4.3453447e-02 205s
1021119 PPushes remaining with PInf 3.6672116e-02 210s
1008277 PPushes remaining with PInf 3.4856467e-02 215s
996812 PPushes remaining with PInf 3.1875117e-02 220s
985507 PPushes remaining with PInf 3.2909975e-02 225s
973167 PPushes remaining with PInf 3.2874683e-02 230s
961476 PPushes remaining with PInf 3.2855519e-02 235s
949399 PPushes remaining with PInf 3.3170365e-02 240s
938110 PPushes remaining with PInf 3.3569918e-02 245s
925661 PPushes remaining with PInf 3.0502401e-02 250s
914401 PPushes remaining with PInf 2.5899016e-02 255s
902600 PPushes remaining with PInf 2.1856312e-02 260s
891822 PPushes remaining with PInf 2.1640191e-02 265s
879998 PPushes remaining with PInf 1.8411472e-02 270s
868611 PPushes remaining with PInf 1.4766664e-02 275s
858382 PPushes remaining with PInf 1.7747901e-02 280s
847399 PPushes remaining with PInf 1.3950302e-02 285s
837565 PPushes remaining with PInf 1.0254122e-02 290s
830407 PPushes remaining with PInf 8.5953304e-03 295s
820344 PPushes remaining with PInf 6.5503050e-03 300s
810558 PPushes remaining with PInf 5.3502447e-03 305s
799131 PPushes remaining with PInf 3.8958003e-03 310s
787141 PPushes remaining with PInf 2.2179265e-03 315s
776371 PPushes remaining with PInf 2.6974525e-03 320s
765314 PPushes remaining with PInf 1.7614358e-03 325s
754762 PPushes remaining with PInf 3.1509939e-03 330s
745416 PPushes remaining with PInf 1.5609430e-03 335s
734734 PPushes remaining with PInf 1.4279799e-03 340s
725567 PPushes remaining with PInf 1.0821299e-03 345s
713475 PPushes remaining with PInf 1.3634131e-03 350s
701287 PPushes remaining with PInf 1.1803179e-03 355s
691705 PPushes remaining with PInf 1.0964983e-03 360s
679554 PPushes remaining with PInf 1.1098449e-03 365s
665826 PPushes remaining with PInf 1.0381580e-03 370s
653776 PPushes remaining with PInf 1.0268389e-03 375s
639812 PPushes remaining with PInf 8.2636462e-04 380s
625883 PPushes remaining with PInf 7.7542182e-04 385s
609217 PPushes remaining with PInf 6.7895259e-05 390s
598346 PPushes remaining with PInf 6.9935285e-06 395s
586725 PPushes remaining with PInf 6.9935285e-06 400s
573057 PPushes remaining with PInf 6.9935285e-06 405s
556788 PPushes remaining with PInf 6.9935285e-06 410s
539641 PPushes remaining with PInf 6.9935285e-06 415s
523726 PPushes remaining with PInf 6.9935285e-06 420s
508023 PPushes remaining with PInf 6.9935285e-06 425s
493187 PPushes remaining with PInf 1.5648923e-06 430s
478173 PPushes remaining with PInf 4.1393174e-05 435s
464650 PPushes remaining with PInf 3.9828281e-05 440s
449088 PPushes remaining with PInf 0.0000000e+00 445s
433163 PPushes remaining with PInf 0.0000000e+00 450s
420783 PPushes remaining with PInf 0.0000000e+00 455s
408606 PPushes remaining with PInf 0.0000000e+00 460s
395025 PPushes remaining with PInf 0.0000000e+00 465s
380501 PPushes remaining with PInf 0.0000000e+00 470s
366685 PPushes remaining with PInf 0.0000000e+00 475s
349324 PPushes remaining with PInf 0.0000000e+00 480s
332283 PPushes remaining with PInf 0.0000000e+00 485s
316965 PPushes remaining with PInf 0.0000000e+00 490s
300431 PPushes remaining with PInf 0.0000000e+00 495s
286153 PPushes remaining with PInf 0.0000000e+00 500s
271912 PPushes remaining with PInf 0.0000000e+00 505s
257906 PPushes remaining with PInf 0.0000000e+00 510s
244011 PPushes remaining with PInf 0.0000000e+00 515s
230781 PPushes remaining with PInf 0.0000000e+00 520s
217961 PPushes remaining with PInf 0.0000000e+00 525s
204581 PPushes remaining with PInf 0.0000000e+00 530s
191310 PPushes remaining with PInf 0.0000000e+00 535s
177643 PPushes remaining with PInf 0.0000000e+00 540s
163415 PPushes remaining with PInf 0.0000000e+00 545s
150022 PPushes remaining with PInf 0.0000000e+00 550s
135718 PPushes remaining with PInf 0.0000000e+00 555s
122436 PPushes remaining with PInf 0.0000000e+00 560s
108524 PPushes remaining with PInf 0.0000000e+00 565s
93842 PPushes remaining with PInf 0.0000000e+00 570s
79504 PPushes remaining with PInf 0.0000000e+00 575s
64526 PPushes remaining with PInf 0.0000000e+00 580s
48050 PPushes remaining with PInf 0.0000000e+00 585s
34381 PPushes remaining with PInf 0.0000000e+00 590s
20228 PPushes remaining with PInf 0.0000000e+00 595s
5301 PPushes remaining with PInf 0.0000000e+00 600s
0 PPushes remaining with PInf 0.0000000e+00 603s
Push phase complete: Pinf 0.0000000e+00, Dinf 3.2233174e-07 603s
Root simplex log...
Iteration Objective Primal Inf. Dual Inf. Time
1235076 6.6448521e+05 0.000000e+00 0.000000e+00 603s
Crossover time: 449.92 seconds (85.40 work units)
Concurrent spin time: 0.03s
Solved with barrier
Root relaxation: objective 6.644852e+05, 1235076 iterations, 545.81 seconds (111.84 work units)
Nodes | Current Node | Objective Bounds | Work
Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time
0 0 664485.208 0 1037 -0.00000 664485.208 - - 790s
H 0 0 441000.00000 664485.208 50.7% - 791s
H 0 0 661500.00000 664485.208 0.45% - 948s
0 0 664485.208 0 1095 661500.000 664485.208 0.45% - 2670s
0 0 - 0 661500.000 664485.208 0.45% - 3580s
Cutting planes:
MIR: 1
Zero half: 1
RLT: 2
Explored 1 nodes (1324999 simplex iterations) in 3581.14 seconds (1162.51 work units)
Thread count was 8 (of 12 available processors)
Solution count 3: 661500 441000 -0
Time limit reached
Best objective 6.615000000000e+05, best bound 6.640000000000e+05, gap 0.3779%
User-callback calls 23716, time in user-callback 0.30 secthank you
-
Hi Pauline,
I can see in the first log that after the push phase there is a large primal infeasibility:
Push phase complete: Pinf 3.7635916e+02, Dinf 4.1848068e-08 238sThen the simplex algorithm kicks in to try and clean up this infeasibility… and it's not performing great. This is what is causing such a difference in timings. In the second log there is no large infeasibility and we jump straight into the branch and bound tree.
For some background it is probably worth reviewing the following two articles:
* Why does Gurobi perform differently on different machines?
* What is performance variability?
So it is plausible that sometimes the Linux machine will perform well and sometimes it won't, and the same goes for Windows.
To explore this properly you would need to run the model with several different values of Seed, on both machines, then compare the logs. If you see the Linux machine consistently ending up with large infeasibilities after the push phase, and Windows doesn't, then perhaps it warrants further investigation.
- Riley
0
Please sign in to leave a comment.
Comments
1 comment