Smart backup of one folder

What is the best way to smart backup a 120GB and growing folder to a portable hard drive?

I have a 250 WD portable hard drive and i would like to backup my TVshow/movies folder so that i can have a full backup when i use my laptop. All the files are in one folder on my desktop, i add a movie every 1-2 days and a tvshow (from my dvr) daily. Right now i just drag it and drop it to my portable hard drive but that takes to long. The perfect thing would be something like time machine only for that folder (without the going in time).

Thanks.

 

I have tried all three products and i would like to say that i like ChronoSync the most. It worked great and saved me a lot of time.

I basically have one folder with everything related to TV Shows and movies in it. I have a folder for every tv show, type of movie (comedy, action) and random stuff. My main problem is that i add files daily to it, sometimes its ten files while another day might be one. It is very hard for me to know what i updated unless i right them down every single time.

What i would do is delete the folder from my portable and then load the new one every time i wanted to use my laptop which took a lot of time. Now i just plug it in and open the saved setting from ChronoSync and boom, the new files get updated. I would recommend this product to anyone who has more then one mac and needs to sync them.