Are you sure ProcessCaching isn't something added by you? I just grep'ed through the settings for both 3.7 and 3.8 (trunk) and I didn't find any setting with that name.
EDIT: It appears to be a very old setting that no longer exists in the currently supported version of eZ publish. 3.0 and/or early 3.1 era. It was related to the template system at the time. It probably still exists because you upgraded all the way, or you're running a museum version of eZ publish ;-)
It was something that was introduced with v3.1, at least that’s what I understood out of the forum post I found that setting in.
It's just me trying to tweak ez as much as possible.
I'm down at 0,4+ / 0,16+ sec. without / with ViewCaching enabled.. Currently waiting for a new version of eaccelerator that supports amd64 and dualcore, so I can swap out apc :)