What is the Fastest Method for High Performance Sequential File I/O in C++?

Question

Assuming the following for...
Output:
The file is opened...
Data is \'streamed\' to disk. The data in memory is in a large contiguous buffer. It is

Answer 1

As you noted above it all depends on the machine / system / libraries that you are using. A fast solution on one system may be slow on another.

A general guideline though would be to write in as large of chunks as possible.
Typically writing a byte at a time is the slowest.

The best way to know for sure is to code a few different ways and profile them.