During each file I/O operation, LabVIEW calls the operating system (OS) and requests a data transfer to and from a file on a disk. Sending data to or receiving data from a disk may take a few milliseconds to complete. These milliseconds can accumulate because LabVIEW must call the OS each time you write a line to a file or request to read a file. To avoid these timely repetitions, most OS file systems provide a buffer to temporarily hold each piece of data waiting to be read or written to a file. When the buffer is full, the OS performs a single file I/O operation. This technique is known as buffering and LabVIEW enables it by default. Buffering reduces the number of times the OS must access the disk and expend processing time.
Sometimes, you can achieve faster data streaming rates if you disable buffering. For example, you may use a Redundant Array of Independent Disks (RAID) to increase processing speed. A RAID is a set of hard disks acting as a single disk that the OS can simultaneously access, taking less time to read or write data. If you access a RAID with buffering enabled, LabVIEW can take more time to copy data to the OS than the OS takes to actually write the data to the disk. You can disable buffering with the disable buffering input of the Open/Create/Replace File function to avoid these data copies and force the OS to send data directly to disk.
However, if you disable buffering, you must make sure the following conditions are true: