Performance of fwrite and write size

Question

I\'m writing out a large numerical 2 dimensional array to a binary file (final size ~75 MB).

I\'m doing this on a linux system. First, is there a better method or s

Answer 1

One chunk is faster. There are several reasons for that:

1) writing to HDD means also maintaining "up to date" all the additional informations in the file system (timestamp, file size, used cluster, locks, etc), so there is some overhead associated with each file access (especially write access).

2) Disk I/O is slow, and so OS usually tries to implement some caching on its side. This means that each time you use file I/O there will be additional checks if it's cached, if it should be cached, and so on.