Specifies the format of the tracefile. ASCII is the traditional Vampir file format where all trace data is written into one file. It is human-readable.
The Structured Trace File (STF) is a binary format which supports storage of trace data in several files and allows Intel Trace Analyzer to analyze the data without loading all of it, so it is more scalable. Writing it is only supported by the Intel Trace Collector at the moment.
One trace in STF format consists of several different files which are referenced by one index file (
.stf). The advantage is that different processes can write their data in parallel (see
SINGLESTFrolls all of these files into one (
.single.stf), which can be read without unpacking them again. However, this format does not support distributed writing, so for large program runs with many processes the generic STF format is better.