Is there any software like 'Primo Cache'? I've used PrimoCache on Windows.
Specifically Defer Write feature not only for performance, 

I've used it for drive endurance.

As a switcher from Windows to Mac, I can handle RamDisk thing now, but I can't find alternatives to this software or feature on OS X.
Apple's Fusion Drive technology encompasses some of what PrimoCache does, in addition to the design of the filesystem itself. Tetsujin's comment is right on. Apple's disk interface is well thought out, robustly designed, and doesn't need any external 'aids' to caching disks for performance sake.