EES 64-bit Professional License

The Commercial and Professional versions of EES are 32-bit Windows executable programs that are designed to operate on both 32-bit and 64-bit WIndows operating systems, such as Windows XP, Windows Vista, and Windows 7/8/10. The 64-bit Professional version is a different program that operates in exactly the same manner as the 32-bit versions except that it can do calculations faster and it allows a maximum of 24,000 variables, compared to 12,000 variables in the 32-bit Professional version. Calculation speeds for the 64-bit version can be a up to 4 times faster than the 32-bit Professional version for computationally-intensive problems.

Please note the following information before ordering a 64-bit license file.

  1. The 64-bit version (EES64.exe) can only operate on a 64-bit Windows operating system, e.g, Windows 10 and 11 64 bit. It will not work on any 32-bit operating system.

  2. A 64-bit license (EES.DFT64) file is required to run the 64-bit version. This file can be purchased from our Order page. Note that a Professional license with a current subscription to Instant Update and Technical Support (IUTS) service is required in order to obtain a 64-bit license file.

  3. If your Instant Update and Technical Support subscription is current, the 64-bit installation file (SETUP_EES64.exe) can be downloaded from our website by entering EES64_XXXX as the login, where XXXX is your existing EES license number. The password and email address provided when the Professional version was purchased must also be entered. Once installed, the EES64.exe will require the XXXX.DFT64 (license) file to be located in the same folder as the EES64.exe program.

  4. Both the 32-bit and 64-bit versions of EES can be installed on the same computer.

  5. There is no 64-bit Commercial version.

  6. The 64-bit version saves EES files with the .EES64 file name extension. EES64 files are identified by the file name extension and the yellow EES 64 icon. Double-clicking on an EES64 file will start the 64-bit version of EES. The 32-bit version of EES cannot read .EES64 files.

  7. The 32-bit versions of EES do floating point calculations using extended floating point numbers having 80 bits of numerical precision. The 64-bit version uses doubles, which are floating point numbers having 64 bits of precision. As a result, the 32-bit version provides greater precision and allows larger numerical values than the 64-bit version. The largest number that the 64-bit version can handle is approximately 1.7E308. The use of 64-bit doubles is the major reason that the 64-bit version calculates faster than the 32-bit version.

  8. Library files in the 64-bit version are saved with the .LIB64 file name extension. Similarly, EES Lookup files, external functions and procedures are identified with a 64 in the file name extension, e.g., .LKT64, .FDL64, .DLF64, and .DLP64. None of Library files developed for the 64-bit version can be directly read by the 32-bit version because of the different format of the floating point numbers.

  9. The 64-bit version of EES can read any 32-bit or 64-bit EES, Library or Lookup table file. However, the conversion of information in the 32-bit file to equivalent 64-bit information can be slow for large files. After converting a 32-bit file, it should be saved as a 64-bit file so that is will be read quickly the next time it is opened.

  10. The 64-bit version can save all EES, Library and Lookup tables files in a format that can be read by the 32-bit Commercial and Professional versions. EES is programmed to save files in the 32-bit format if the file name extension is .EES or .LIB instead of .EES64 or .LIB64. The Open and Save As dialogs provide a dropdown control to select various file types, including the 32-bit formats.

  11. The 64-bit version can not read external library files (.FDL, .DLP, .DLF, .DLL) that were created for the 32-bit version. It is necessary to recompile these external library files with a 64-bit compiler and save them with .FDL64, .DLP64, .DLF64, and .DLL64 file name extensions.

  12. The EES_REFPROP interface (EES_REFPROP.DLL) must be upgraded to operate with the 64-bit version. The upgrade can be ordered from our Order page.

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