Introduction
The hardware on which FME runs and its configuration can greatly affect performance. For other performance tuning tips and tricks, see the Performance Tuning FME article.
Technical Specifications
Technical specifications for FME can be found in the FME Platform Technical Specifications article.
System Configuration and the FME Log File
An FME log file contains important information about the system configuration and is a good place to look when fine-tuning performance.
Temporary Directory Location
One of the first items of importance in a log file is the temporary directory:
2026-05-11 14:06:21|0.0|0.0|INFORM|FME Configuration: Temporary folder is `C:\Users\FMEEXAM~1\AppData\Local\Temp\wbrun_1778522781301_18300\fmetmp_0', set from environment variable `FME_TEMP'You'll also see a line commenting on the amount of disk space available in that directory...
2026-05-11 14:06:21|0.0|0.0|INFORM|System Status: 769.27 GB of disk space available in the FME temporary folder (C:\Users\FMEEXAM~1\AppData\Local\Temp\wbrun_1778522781301_18300\fmetmp_0)When FME runs a large translation, it often requires significant temporary disk space. Available disk space is important, but so is the speed of any disk activity.
Point your temporary directory to a fast disk with ample space (the more, the better). An SSD (solid-state drive) disk is recommended. See the Setting a temporary file location for FME article for how to set FME_TEMP. Where possible, use a different disk from the one used by the operating system.
You could also try a RAM drive (also called a RAM disk) for your temporary directory, although the benefits are more apparent on memory-limited 32-bit systems. Modern systems should be using excess memory for caching anyway.
Some operating systems default to a RAM drive for the temp drive. This means that FME caching may consume RAM, which can affect performance (depending on how much is available on the system). Setting FME_TEMP will force FME to cache to a physical drive, which may improve performance.
Setting the FME_TEMP and FME_HOME paths to a network drive results in performance degradation. For optimal performance, ensure that these paths are local. A warning will appear in the log if these paths are set to a network drive.
FME Configuration: Temporary folder `\\networkdrive\Test\temp\wbrun_1648504346434_59492\fmetmp_0` is on a network drive. It is recommended to set FME_TEMP to a local drive for best performance System Status
Other lines in the FME log tell us the status of the machine in terms of platform, hardware, and encoding:
Operating System: Microsoft Windows 11 Pro 64-bit (Build 26200)
FME Platform: WIN64
System Status: 769.27 GB of disk space available in the FME temporary folder (C:\Users\FMEEXAM~1\AppData\Local\Temp\wbrun_1778522781301_18300\fmetmp_0)
System Status: 63.46 GB of physical memory available
System Status: 253.83 GB of virtual memory availablePhysical memory is the amount of memory installed in the system. Here, it is 63.46 GB. Virtual memory is a function of the operating system’s memory management system. It's a technique in which the system swaps data to compensate for low-memory conditions. Here, it has 253.83 GB of virtual memory.
Obviously, more physical and virtual memory leads to improved system performance.
Virtual Machines
A Virtual Machine (VM) is a computer system that does not physically exist, but is emulated on a physical computer. A Virtual Machine can provide superior performance on a temporary basis, which is ideal for running FME workspaces with large amounts of data processing.
However, FME deployed on a Virtual Machine can sometimes run slower than on an equivalent desktop machine. This is often due to a poorly configured VM environment in which several VMs share resources designed for a single-use machine, such as network bandwidth, memory, and shared drives.
Network latency within the VM cluster may cause issues when accessing a database from a VM. The host machine must be capable of supporting the number of guest VMs, including the network bandwidth required for database access and the network file system.
Past experience has shown that disabling dynamic memory management in the virtual machine environment can improve memory allocation and performance.
Machine Comparisons
Sometimes, the same workspace behaves differently across systems, even when the specification appears identical. If you see different performance characteristics on different machines, then it might be because of one of these differences:
- Is one computer physical and the other virtual?
- Is the operating system the same, with the same version and the same OS updates (service packs)?
- Is there a larger or faster CPU cache to access data more quickly on one system?
- Is the version, build, and bitness (32-bit vs 64-bit) of FME the same?
- Is the FME temporary directory on the same sort of drive (local/network or HDD/SSD)?
- Are the data sources on the same sort of drive (local/network or HDD/SSD)?
- Does each FME installation have the same access permissions to the source/destination data?
- Is one system running extra software that could be consuming resources?
- Is one system running potentially blocking services like a firewall or antivirus?
- Does one machine have better network bandwidth?
- Is one machine physically closer to the database server than the other?
- Is there competition for memory, disk, network, CPU, or other limiting resources?
In general, performance improves when many factors remain static (consistent), and those that cannot be controlled should be minimized. Using different machines removes most of that control.
32-bit Windows and 32-bit FME
FME 2021.2 was the last release to support 32-bit and is no longer supported. Please see the FME 32-bit Windows Support article for more information. For those who still use 32-bit Windows, the operating system limits the memory available to a single process to 2 GB. This low number can negatively affect performance. You may increase the amount of memory available by setting the /3GB Switch.
Sometimes the 32-bit FME version is used because it supports an older format that the 64-bit version does not. In this case, you can use the 32-bit FME version running on a 64-bit workstation to access greater memory resources. However, overall, the recommendation is to use the FME 64-bit version running on a 64-bit processor.
Use the 64-bit FME version wherever possible. However, if the 32-bit FME version is unavoidable, either increase the available memory on the 32-bit Windows machine with the /3GB switch or use a 64-bit machine.