Concerning Windows 7 x64 and Windows 10 x64 splitting the pagefile system does nothing as in a raid0 like condition. It is first grabbed, first served by the least active drive. The rule for Windows x64 is a pagefile 1.5 times the size. I am operating a machine that has 64 gigs and I don't even need a pagefile that size. Setting up a fast drive to handle all my windows temp files, ie cache files, and one single pagefile works great. The purpose of this drive is only for the use of windows and adobe temp services. I run applications on a powerful three drive raid0 and my os is on an SSD. There are people who believe that a pagefile is not necessary but these folks don't live in a powerfully creative world where powerful applications must have a pagefile such as the newer adobe cc 2017 tools and 3D CAD machines.
What is interesting Microsoft states a minimum 300 MB pagefile should be set up on the primary drive, your OS drive and the brunt on another drive. Adobe says that temp and pagefiles should be located other than an os drive or the application drive. They have been saying this since the beginning of time.