How many games can I download to my 1tb Hybrid Hard Drive?

So I want to know how manhy games its okay to download to my desktop,
I have a lenovo 1Tb Hybrid Hard Drive 8GB of Ram.
I only have Age of Empires 3, the Asian dynasty and the Warchiefs extesions that have on Disc.
Also downloaded on Steam Dota 2 and i'm planning to download Aion with steam is my computer going to be fine and not run slow, or how much space of my computer do games have to take so it can start effecting the performance?
Sorry i'm new to PC Gaming, but I really enjoy and would like some common knowledge about computers so if anyone has any ideas please enlighten me.

You can install as many games as will fit on the hard drive and still provide enough space for system operation. You typically don't want a hard drive that has less than 5 or 10 gigs of space available. If you have a 1 TB drive and you have it 90% full, it's time to start considering moving to a 2, 3, or 4 TB drive. Or upgrading to a RAID array, which uses multiple drives.