What is that Hard Drive Program?

[Daemic]

What is the name of the program that you can see the breakdown of your hard drive data visually with the colored blocks? It then breaks it down by folder and file type to see what is being used by what. I remember I got it from an LTT video but after some reformatting I can't remember the name of the program. Additionally, is there a list of benchmark utilities that LTT and forum users utilize? I would benefit from a checklist 

[Craftyawesome]

I use WinDirStat, but there are multiple similar programs to that.

[Quinnell]

I used to use WinDirStat but it got really sluggish on some systems.  I use WizTree now.

[Daemic]

That's it! WinDirStat, I couldnt remember what it was called. Thank you so much guys.

2 minutes ago, Quinnell said:

I used to use WinDirStat but it got really sluggish on some systems.  I use WizTree now.

What do you mean by Sluggish? Just slow to read or eats up resources to run?

[Kilrah]

Still never found better than the 20 year old SpaceMonger 1.4.0 even if it sometimes crashes when deleting stuff from within it. 

[LWM723]

TreeSizeFreePortable works very good