Physical installs, you will have to select custom instal location, sometimes under custom install when install screen steps appear.
With steam, you simply install it to the HDD with steam install, then all games will installed under steamapps in steam folder on HDD.
Origin is a little bit more stupid, you have to set your install location in setting under general/downloaded games.
You can set up your game installers to if you like.
You don't need Origin itself on same disk. but its up to you if you want to run it off the ssd or hdd.
For me its set for.
D:\Origin Games\
If your installing from disk its safe to say it will be installed in location set, but since i cant remember don't quote me on that so refer to physical installs with a custom location but im pretty sure.
D is my raid array and the game will be installed under D:\Origin Games\Battlefield 3
For application without a install procedure you simply copy the executable and any configs files along with it to a custom named folder.
Such as intel burn test, name folder and copy paste then run.
Hope that's clear.
;) 
