Scratch files

From Vd

Gaussian uses a scratch file for temporary storage. This is called a RWF file which means ReadWriteFile. A file accessed continuously during a run. This is a typical random access file. Typically the most high performing random access device is the local disk. This has random access (read 128k records) in excess of 20 MB/s while GPFS has less than 6 MB/s for the same access. A testrun yielded an average record size of 100 k for the RWF file access, however a large fraction of the access were far shorter records (32% less than 4k). More data about local versus mounted scratch disk can be found at benchmarks of Titan.