One Hertz

Everytime I load or save a single file to/from my editor.
The point is that if the stripe size doesn't match your common file size one ends up not utilizing more than one SSD.
(one cannot tell which SSD a file is stored on and in theory all of your 10MB small files could be on one of the SSD's, using a small stripe size one is guaranteed that the file is distributed on more than one SSD)