DIMACS benchmark set

This is a selected set of instances form the Second DIMACS Implementation Challenge (1992-1993).
In the following table, the clique number ω(G) corresponds to the global optimum or to the lower bound as indicated by the instance generator.
For some instances the lower bound has been confirmed to coincide with the global optimum. For such instances, the clique number is followed by a *.
The exact algorithms that confirmed the bound are reported later on this page.

Instanceω(G)Best knownNodesEdgesGraph degreesBest degrees
MedianIQRMedianIQR
C125.934*341256 963112.0(5.00)114.5(4.75)
C250.944*4425027 984224.0(6.00)227.0(5.00)
C500.9≥ 5757500112 332449.0(9.00)455.0(9.00)
C1000.9≥ 68681 000450 079900.0(13.00)907.0(11.25)
C2000.9≥ 80802 0001 799 5321 800.0(18.00)1 803.0(15.25)
DSJC1000_515151 000499 652500.0(20.00)503.0(23.00)
DSJC500_51313500125 248250.0(16.00)259.0(14.00)
C2000.516*162 000999 836999.0(30.00)1 006.0(11.50)
C4000.518*184 0004 000 2682 001.0(42.00)2 002.0(40.75)
MANN_a2712612637870 551374.0(0.00)374.0(0.00)
MANN_a453453451 035533 1151 031.0(0.00)1 031.0(0.00)
MANN_a811 100*1 1003 3215 506 3803 317.0(0.00)3 317.0(0.00)
brock200_212122009 87699.0(10.00)101.0(11.00)
brock200_4171720013 089131.0(8.00)134.0(6.00)
brock400_2292940059 786299.0(10.00)299.0(9.00)
brock400_4333340059 765299.0(11.00)299.0(9.00)
brock800_22424800208 166521.0(18.00)516.5(20.25)
brock800_42626800207 643519.0(18.25)512.0(20.25)
gen200_p0.9_44444420017 910180.0(8.00)179.5(4.25)
gen200_p0.9_55555520017 910179.0(7.25)179.0(5.50)
gen400_p0.9_55555540071 820360.0(13.25)359.0(6.00)
gen400_p0.9_65656540071 820361.0(14.00)359.0(9.00)
gen400_p0.9_75757540071 820359.0(13.00)359.0(8.00)
hamming10-440401 024434 176848.0(0.00)848.0(0.00)
hamming8-4161625620 864163.0(0.00)163.0(0.00)
keller411111719 435110.0(8.00)112.0(17.00)
keller52727776225 990578.0(38.00)578.0(33.00)
keller6≥ 59593 3614 619 8982 724.0(50.00)2 724.0(50.00)
p_hat300-18830010 93373.0(39.00)103.0(20.00)
p_hat300-2252530021 928146.5(73.00)213.0(18.00)
p_hat300-3363630033 390224.0(38.00)251.0(15.25)
p_hat700-1111170060 999174.5(87.00)250.0(22.50)
p_hat700-24444700121 728353.0(177.50)508.0(31.50)
p_hat700-362*62700183 010526.0(89.00)602.0(14.00)
p_hat1500-112121 500284 923383.0(197.00)509.0(82.00)
p_hat1500-265*651 500568 960763.0(387.00)1 100.0(37.00)
p_hat1500-394*941 500847 2441 132.5(192.00)1 297.5(25.75)

The instances can be downloaded from the DIMACS ftp site, or directly from here. Archives containing the whole dataset and the selected instances are available below.

Instance families and generators

Below a brief description mostly cut-and-pasted from the headers of the instance files. Much more details about the instances can be found in the headers, in the README files of the generators, and in the linked papers.

Recent new optima

Bounds confirmed by exact algorithms

The following instance bounds have been confirmed to be optimal by exact algorithms. The list of algorithms below is not exhaustive, and in some cases it could be that the exact algorithms reported are not the first ones to have confirmed the bounds. The list of references in this section is updated every time someone brings to my attention that a bound has been confirmed by a particular algorithm.

Instances

If you have found other cliques or improved the best known solution, please let me know, so that I can update this page.

C125.9
Graph with 125 nodes, 6 963 edges, and ω(G)34*.Best-known solution hassize 34.
Available in DIMACS ascii format, or DIMACS binary format.
C250.9
Graph with 250 nodes, 27 984 edges, and ω(G)44*.Best-known solution hassize 44.
Available in DIMACS ascii format, or DIMACS binary format.
C500.9
Graph with 500 nodes, 112 332 edges, and ω(G)≥ 57.Best-known solution hassize 57.
Available in DIMACS ascii format, or DIMACS binary format.
C1000.9
Graph with 1 000 nodes, 450 079 edges, and ω(G)≥ 68.Best-known solution hassize 68.
Available in DIMACS ascii format, or DIMACS binary format.
C2000.9
Graph with 2 000 nodes, 1 799 532 edges, and ω(G)≥ 80.Best-known solution hassize 80.
Available in DIMACS ascii format, or DIMACS binary format.
DSJC1000_5
Graph with 1 000 nodes, 499 652 edges, and ω(G)= 15.Best-known solution hassize 15.
Available in DIMACS ascii format, or DIMACS binary format.
DSJC500_5
Graph with 500 nodes, 125 248 edges, and ω(G)= 13.Best-known solution hassize 13.
Available in DIMACS ascii format, or DIMACS binary format.
C2000.5
Graph with 2 000 nodes, 999 836 edges, and ω(G)16*.Best-known solution hassize 16.
Available in DIMACS ascii format, or DIMACS binary format.
C4000.5
Graph with 4 000 nodes, 4 000 268 edges, and ω(G)18*.Best-known solutions havesize 18.
Available in DIMACS ascii format, or DIMACS binary format.
MANN_a27
Graph with 378 nodes, 70 551 edges, and ω(G)= 126.Best-known solution hassize 126.
Available in DIMACS ascii format, or DIMACS binary format.
MANN_a45
Graph with 1 035 nodes, 533 115 edges, and ω(G)= 345.Best-known solutions havesize 345.
Available in DIMACS ascii format, or DIMACS binary format.
MANN_a81
Graph with 3 321 nodes, 5 506 380 edges, and ω(G)1 100*.Best-known solution hassize 1 100.
Available in DIMACS ascii format, or DIMACS binary format.
brock200_2
Graph with 200 nodes, 9 876 edges, and ω(G)= 12.Best-known solution hassize 12.
Available in DIMACS ascii format, or DIMACS binary format.
brock200_4
Graph with 200 nodes, 13 089 edges, and ω(G)= 17.Best-known solution hassize 17.
Available in DIMACS ascii format, or DIMACS binary format.
brock400_2
Graph with 400 nodes, 59 786 edges, and ω(G)= 29.Best-known solution hassize 29.
Available in DIMACS ascii format, or DIMACS binary format.
brock400_4
Graph with 400 nodes, 59 765 edges, and ω(G)= 33.Best-known solution hassize 33.
Available in DIMACS ascii format, or DIMACS binary format.
brock800_2
Graph with 800 nodes, 208 166 edges, and ω(G)= 24.Best-known solution hassize 24.
Available in DIMACS ascii format, or DIMACS binary format.
brock800_4
Graph with 800 nodes, 207 643 edges, and ω(G)= 26.Best-known solution hassize 26.
Available in DIMACS ascii format, or DIMACS binary format.
gen200_p0.9_44
Graph with 200 nodes, 17 910 edges, and ω(G)= 44.Best-known solution hassize 44.
Available in DIMACS ascii format, or DIMACS binary format.
gen200_p0.9_55
Graph with 200 nodes, 17 910 edges, and ω(G)= 55.Best-known solution hassize 55.
Available in DIMACS ascii format, or DIMACS binary format.
gen400_p0.9_55
Graph with 400 nodes, 71 820 edges, and ω(G)= 55.Best-known solution hassize 55.
Available in DIMACS ascii format, or DIMACS binary format.
gen400_p0.9_65
Graph with 400 nodes, 71 820 edges, and ω(G)= 65.Best-known solution hassize 65.
Available in DIMACS ascii format, or DIMACS binary format.
gen400_p0.9_75
Graph with 400 nodes, 71 820 edges, and ω(G)= 75.Best-known solution hassize 75.
Available in DIMACS ascii format, or DIMACS binary format.
hamming10-4
Graph with 1 024 nodes, 434 176 edges, and ω(G)= 40.Best-known solution hassize 40.
Available in DIMACS ascii format, or DIMACS binary format.
hamming8-4
Graph with 256 nodes, 20 864 edges, and ω(G)= 16.Best-known solution hassize 16.
Available in DIMACS ascii format, or DIMACS binary format.
keller4
Graph with 171 nodes, 9 435 edges, and ω(G)= 11.Best-known solution hassize 11.
Available in DIMACS ascii format, or DIMACS binary format.
keller5
Graph with 776 nodes, 225 990 edges, and ω(G)= 27.Best-known solution hassize 27.
Available in DIMACS ascii format, or DIMACS binary format.
keller6
Graph with 3 361 nodes, 4 619 898 edges, and ω(G)≥ 59.Best-known solution hassize 59.
Available in DIMACS ascii format, or DIMACS binary format.
p_hat300-1
Graph with 300 nodes, 10 933 edges, and ω(G)= 8.Best-known solution hassize 8.
Available in DIMACS ascii format, or DIMACS binary format.
p_hat300-2
Graph with 300 nodes, 21 928 edges, and ω(G)= 25.Best-known solution hassize 25.
Available in DIMACS ascii format, or DIMACS binary format.
p_hat300-3
Graph with 300 nodes, 33 390 edges, and ω(G)= 36.Best-known solution hassize 36.
Available in DIMACS ascii format, or DIMACS binary format.
p_hat700-1
Graph with 700 nodes, 60 999 edges, and ω(G)= 11.Best-known solution hassize 11.
Available in DIMACS ascii format, or DIMACS binary format.
p_hat700-2
Graph with 700 nodes, 121 728 edges, and ω(G)= 44.Best-known solution hassize 44.
Available in DIMACS ascii format, or DIMACS binary format.
p_hat700-3
Graph with 700 nodes, 183 010 edges, and ω(G)62*.Best-known solution hassize 62.
Available in DIMACS ascii format, or DIMACS binary format.
p_hat1500-1
Graph with 1 500 nodes, 284 923 edges, and ω(G)= 12.Best-known solution hassize 12.
Available in DIMACS ascii format, or DIMACS binary format.
p_hat1500-2
Graph with 1 500 nodes, 568 960 edges, and ω(G)65*.Best-known solution hassize 65.
Available in DIMACS ascii format, or DIMACS binary format.
p_hat1500-3
Graph with 1 500 nodes, 847 244 edges, and ω(G)94*.Best-known solution hassize 94.
Available in DIMACS ascii format, or DIMACS binary format.
last update, 26 Oct 2015