Today there are many tool for split pst file but trust me i suggest you best ever pst split tool which can instantly convert your pst file without wasting you costlytime. Any type of users can easily split pst file through this tool because you don't need any technical knowledge for this tool. this tool Creates several independent PST files by splitting large PST file. The user can split large PST file according to date, email type and user nameOriginal formatting and order of mails are retained in the new PST file. It supports splitting of PST file which is password protected, i'm telling you again No extra technical skill is required to use this tool as it uses self explanatory graphical interface.

to checkout this free tool click here:- http://www.undeletepcfiles.com/split-pst-file.html

 

If you're using Outlook Email client application where all your email saved in PST or Personal Storage Table file format then these two thechnique Split and Merge will definitely help you to come back from two major issues:

1. When have large size Outlook PST file.
2. When have large number of Outlook PST file in Outlook account to access.  

Split Technique: This technique will help you to break large size size Outlook PST file in some small PST files so that user can use data of large size file easily. 
Merge Technique: It will allow user combine and merge large number of Outlook email files in one single file.

You can take more information about both two technique from the link: Split and Merge Outlook PST file