Thsnks for your interesting benchmark. That surprised me.

The reason why 8K is "good"... The smallest unit of data that can be written to the disk is called a sector. For a bunch of historical and practical reasons, the most common value seen today is 512 bytes. There is no need for the file system to keep track of such a small unit. So the file system keeps track of blocks of sectors. An extremely common value of this smallest file system data unit is 8Kytes or 16 sectors. A combination of df or du commands can show this on a Unix system. Sorry don't have a Unix sys right now to post an example. If you write a file with one byte in it, it will take 8K of space on the disk. It is more efficient to just start out in the first place with a buffer size that will make the "file system happy" (increment of 8K). Bigger buffers typically help, but there are limits. I suspect not much to be gained once you are past 4*8192 bytes. Yes, sysread would have lower overhead. The OP's situation doesn't sound like any kind of performance issue.

In reply to Re^9: Error binmode() on unopened filehandle by Marshall
in thread Error binmode() on unopened filehandle by RedJeep

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