Will adding a 2nd HDD slow down my PC?

Question

My current PC setup is based on an i5-6400 processor with a 240GB SSD for windows and a 1TB 7200 Baracuda HDD.

I'm thinking of replacing my laptop's HDD (5400 RPM) with a new SSD and then installing the old HDD into my PC as I have a good few hundred GBs of games and will probably run out of space very soon.

Now, my question might be a stupid one, but will adding the slower 2nd HDD decrease overall performance of my PC?
I know load times for software and read times for files that are on the 5400 HDD will be longer, and I'm ok with that. But might windows try to sync the HDDs in any way?

Answer 1

No, the additional hard drive will not slow your computer down. As you said, accessing anything on the slow drive will not be as fast as your Barracuda HDD. Applications that use that disk, like antivirus, backups, indexing, etc will use extra resources on that drive, but it will not be significant in any way.