RealTest is written in the C programming language using the native Windows API (as opposed to MFC or .NET). It was originally a 32-bit application, then for some time had both 32-bit and 64-bit versions. Now only the 64-bit version is maintained.
In many ways, RealTest is a vintage 1990s-style Windows desktop application.
There are no external libraries or components required, so installation is simple and clean.
The only change the installer makes to the Windows Registry is to associate the file types .RTS, .RTR and .RTD with this application.
Persistent settings are stored in the realtest.ini file in the program's installation directory, rather than in the Registry. RealTest must therefore be installed to a directory which has write permission.
With no data loaded, RealTest occupies less than 10mb of RAM. Data in memory occupies 64 bytes for every bar of every stock, plus 8 additional bytes per bar for each user-created data item in the active script.
In practice, a set of strategies using a universe of all US common stocks going back 10 years can be tested on a computer with 4GB of RAM. For best results when including more than 10 years and/or delisted symbols, 16GB of RAM is recommended.
RealTest will use up to 32 CPU threads if available. Multi-threading is only used for importing data and calculating your custom Data column formulas. The backtest engine is single-threaded but very efficient. Any CPU made in the past decade or so will be fast enough to run lots of tests in a small amount of time.
Your screen should have at least 1920x1080 pixels. RealTest is "DPI-aware" and fully supports higher resolutions such as 4K and/or scaling factors other than 100%.
RealTest also works fine on a cloud-based virtual machine, or a Mac running BootCamp or Parallels.