FAQ: Choosing the 32-bit or 64-bit Version of the ReliaSoft Desktop Applications

This page applies to Version 2020 and earlier.

Prior to Version 2021, all ReliaSoft desktop applications were available in both 32-bit and 64-bit versions; this page answers some frequently asked questions about choosing between these versions. Note that starting in Version 2020, the installer for ReliaSoft desktop applications is always 64-bit, so you must be using a 64-bit version of Windows. 

When do I have a choice?

You can choose which version of the ReliaSoft desktop applications to install if you have any version of Microsoft Office except Office 2010 (32-bit). If you have Microsoft Office 2010 (32-bit), you must install the 32-bit version of the applications.

Note that if you plan to use the optional ReliaSoft Application Programming Interface (API) with VBA, you must have the same bit version of Office and ReliaSoft application installed (i.e., 32-32 or 64-64).

What is the difference?

The terms "32-bit" and "64-bit" refer to how much of your computer's memory (RAM) can be used by applications. The 32-bit version of ReliaSoft applications (like all 32-bit applications) can only use up to 2^32 bytes (approximately 4 gigabytes) of RAM, regardless of how much RAM you have on your PC. 

In contrast, the 64-bit version of ReliaSoft applications can use a theoretical maximum of 2^64 bytes (approximately 16 exabytes) of RAM. However, there is no benefit to the 64-bit version if you do not have more than 4 GB of RAM on your PC.

How does this affect performance?

Complex simulations in BlockSim (and, in version prior to 2020, RENO) are the only activities in which the 64-bit version could provide a performance benefit over the 32-bit version, and only if your PC has sufficient processing power and RAM.

Is one version more stable than the other?

No, because both versions use the same base code and are compiled to either 32-bit or 64-bit.

The only stability issues solved by the 64-bit version are crashes that happen as a result of running out of memory. The 64-bit version allows you to utilize more than 4 GB of RAM if it's available on your PC.

Will I notice differences in the numerical results between versions?

Yes, it is possible that you may notice slight differences in the results provided in one version vs. the other. Computer processors handle 32-bit floating numbers differently from 64-bit floating numbers, and this is especially noticeable when higher order calculations (such as logarithms, exponentiation, etc.) are performed. This results in round-off discrepancies.

The bottom line is that you will never get a 32-bit and a 64-bit program to exactly agree to the nth decimal place when there are floating point calculations involved.

Can I install the 32-bit and 64-bit versions at the same time?

No. This is not approved nor recommended.

Do I need the 64-bit version if I am connecting to a 64-bit database server?

No. The enterprise database and the application do not have to match.