Gurobi mixed-integer programming speed

Gurobi vendor-reported MILP speedup

Click a point to open the vendor announcement.

Definition

Mixed-integer programming is the workhorse of applied optimization, and solver speed on it is one of the oldest measured algorithmic-progress series. Gurobi recompiles and reruns every released version on one bank of identical machines, so the ratio between versions is machine-independent by construction. The vendor reports both an overall MILP figure for models taking over one second and a larger hard-model figure for those taking over 100 seconds; this series uses the overall figure throughout. The vendor describes a 9,423-model test set, a 10,000-second time limit, and an Intel Xeon E3-1240 v5 at 3.50 GHz with 4 cores, 8 hyper-threads and 32 GB of RAM [@gurobi2026performance].

The fixed-hardware rerun design is Robert Bixby's, from the canonical measurement of solver progress [@bixby2012history], now run by the company he founded. A "discovery" is a released version that solves the same models faster, dated by its announcement, so the unit is a release rather than a paper or a record.

Facts

The vendor's cumulative claim on its performance page moved between release eras:

"a more than 75x speedup on MILP since version 1.1" — Gurobi Optimization, unmatched-performance page, version-10-era capture (version 10 released 2022-11-14) [@gurobi2026performance]

"A 92x speed-up over version 1.1" — Gurobi Optimization, unmatched-performance page, version-13-era capture (version 13 released 2025-11-18) [@gurobi2026performance]

Independent benchmarking of Gurobi ended during the covered window. Hans Mittelmann's public benchmark page records that IBM and FICO demanded removal after 2018, and:

"In August 2024 Gurobi decided to withdraw from the benchmarks as well" — Hans D. Mittelmann, Benchmarks for Optimization Software, plato.asu.edu/bench.html, 2024 [@mittelmann2024benchmarks]

The collection-wide cumulative index redraws this series as the cumulative speedup factor over time:

Cumulative vendor-reported speedup factor over time.

Method

There is no fetch.py in this folder. The four percentages are hand-transcribed from prose release announcements, some of them through archive captures, and each new release is read and typed in the same way. Each row carries credit, source and source_url, so the provenance of every percentage is in the data rather than only in this document. check.py recomputes the fact lines above from the CSV.

figure.py reads gurobi-milp-speedups.csv and takes the running product of the release_speedup column in row order, so the plotted quantity is cumulative rather than per-release. The line starts at 1.0 at the beginning of 2022, steps at the year fraction of each date, and each point is labelled from the release column. The whole series is drawn in the collection's vendor grey rather than the human blue, because the figures are the vendor's own and were not independently rerun; the corner note states the cumulative factor and that no AI credit appears in the release notes. The axis is linear and January 2026 onward is shaded, as in every figure here.

Limitations

AI attribution

No AI or language-model credit appears in the version 10 to 13 release announcements as transcribed (announcement URLs carried row by row in the CSV; transcription current to 2026-08-10) [@gurobi2025release13].

Two adjacent AI results in classical combinatorial optimization sit off this series. AE-Kissat-MAB, a solver evolved with a language-model loop, won the 2025 SAT Competition's Main Sequential Track, solving 327 of 400 instances against 321 for the human-written Kissat lineage it descends from [@satcompetition2025results]; it is not placed on any curve in this collection because the competition changes its benchmark set every year. AlphaEvolve's data-centre scheduling heuristic is self-reported to recover about 0.7% of fleet-wide compute, a production heuristic rather than a solver record [@novikov2025alphaevolve].

Sources