**By Hans Mittelmann (mittelmann at asu.edu)**

For many years our benchmarking effort had included the solvers CPLEX, Gurobi, and XPRESS. Through an action by Gurobi at the 2018 INFORMS Annual Meeting this has come to an end. IBM and FICO demanded that results for their solvers be removed and then we decided to remove those of Gurobi as well. CPLEX was in fourteen of the benchmarks, Gurobi and XPRESS in twelve.

A partial record of previous benchmarks can be obtained from this webpage and some additional older benchmarks

* Concorde-TSP with different LP solvers (12-20-2017)*

* Benchmark of Simplex LP solvers (3-17-2019)*

* Benchmark of Barrier LP solvers (2-22-2019)*

* Large Network-LP Benchmark (commercial vs free) (2-27-2019)*

* MILP Benchmark - MIPLIB2017 (3-16-2019)*

* MILP cases that are slightly pathological (1-22-2019)*

* SQL problems from the 7th DIMACS Challenge (8-8-2002)*

* Several SDP codes on sparse and other SDP problems (10-25-2018)*

* Infeasible SDP Benchmark (5-9-2018)*

* AMPL-NLP Benchmark (12-23-2018)*

* Non-commercial convex QP Benchmark (3-4-2019)*

* Binary QPLIB Benchmark (1-28-2019)*

* QPLIB-QCQP Benchmark (2-6-2019)*

* Convex Discrete QPLIB Benchmark (2-17-2019)*