We've just released Analytic Solver® V2022.5 -- a new version of our product line for Excel. Our theme for this release is "even better performance and robustness in our large-scale Solver Engines" -- because the improvements in this release are quite significant, especially for the KNITRO Solver, Xpress Solver, and (very soon) MOSEK Solver Engines. (The Gurobi Solver Engine is also upgraded to version 9.5.2, but we were already shipping version 9.5 in our previous V2022 point releases.) If you are using one of these Solver Engines, we strongly encourage you to click the Download link in the top blue menu bar (login, if you haven't already), and follow the instructions to download and run our latest SolverSetup program. V2022.5 includes other enhancements and fixes as well -- for example if you have a new very-high-resolution video monitor, you'll probably see better-looking versions of certain Analytic Solver dialogs.
You need 64-bit Microsoft Office!
By special arrangement with the software developers -- all of whom have long since moved to 64-bit versions, as we have -- we're still able to support all of our large-scale Solver Engines in both 32-bit and 64-bit versions -- but like all 32-bit software, these Solver Engine versions are limited to working with 4GB of memory. In Analytic Solver® V2022.5, to realize the benefits of the new Xpress Solver version described below, you must be running the 64-bit version of Microsoft Office -- not the 32-bit version. With any luck, you already have 64-bit Office and 64-bit Analytic Solver -- you probably have 16GB to 32GB of memory in your PC, and you need 64-bit Office and Excel to use that memory! But if you're still running 32-bit Office, it's past time to upgrade!
By way of background, it has been more than 12 years since Microsoft Office 2010 became available in both 32-bit and 64-bit versions -- but many companies postponed an upgrade from the 32-bit version to the 64-bit version, because they had their own 32-bit applications or Office add-ins that they wanted to continue to run. For a number of years beyond 2010, Microsoft set the default installation in Office Setup to 32-bit, so that companies wouldn't encounter unexpected problems But now the default installation is 64-bit. It's become harder and harder for us to "source" 32-bit versions of the Solver Engines, and with this new Xpress Solver release, it's become impossible (but you can still use an older 32-bit Xpress version).
To check your own Excel version, just choose File - Account - About Excel -- the top of the dialog box should show either 32-bit or 64-bit. If you still have the 32-bit version, talk to your IT staff if needed, but make it a priority to upgrade to 64-bit.
Enhanced KNITRO Solver Engine
Analytic Solver V2022.5 includes a significantly enhanced version of the KNITRO Solver Engine -- our most powerful Solver for large-scale, smooth nonlinear optimization models. This includes both a new version of the KNITRO Solver itself (V13.1), with significant performance enhancements, better support for multi-start (a good approach to finding the globally optimal solution) and new user options for gradients and mixed-integer nonlinear models, and a series of enhancements to our "KNITRO Solver integration" which transforms Excel models into the internal form accepted by KNITRO -- such as improved calculation of Hessians in Excel, improved handling of bounds, better usage of multicore CPUs, and better support for alldifferent constraints. Most KNITRO users should see performance improvements in this release.
Enhanced Xpress Solver Engine
Analytic Solver V2022.5 includes a significantly enhanced version of the Xpress Solver Engine -- practically "tied with the Gurobi Solver" as our most powerful Solver for large-scale linear mixed-integer optimization models. The internal version number used in the Xpress Solver code has gone from 37.1.3 to 40.1.1 -- so this encompasses several major and minor internal releases. This release has many improvements in MIP (mixed-integer) performance: more advanced MIP presolve, improved logic for branching strategy, separation of Mixed Integer Rounding (MIR) cuts, handling of cliques, new heuristics, improved cut activation and deactivation strategies, better application of strong branching, and an improved sifting algorithm with the Barrier option. Speed improvements are always model-specific, but we expect most Xpress users will see performance improvements in this release.
Coming Very Soon: Enhanced MOSEK Solver Engine
As this is written on July 30, we can't quite yet include the latest version of the MOSEK Solver, their Version 10 -- it is planned for release in mid-August. (Our current Analytic Solver V2022.5 includes MOSEK Version 184.108.40.206.) But we've already done the work to fully integrate and take advantage of MOSEK Version 10, and as soon as we can, we'll create a point release and activate our in-software notification of new versions, so you can "come and get it" (return to Solver.com and download and run SolverSetup one more time). We're covering the MOSEK Solver Version 10 here because its performance improvements over our prior version, notably on linear mixed-integer problems, are very impressive. Under our current pricing, the MOSEK Solver costs the same as our Large-Scale LP Solver Extended, and we expect that, with Version 10, the MOSEK Solver will outperform the LSLP Solver on many models. If you haven't considered the MOSEK Solver in the past, we recommend that you give it a try in late August -- we think you'll be impressed as well!