How many cron job task is too many?

I would like to know your experience. Do you overload your server with too many cron job tasks that it slows down your website server? At what point does your site begin to get unbearably slow due to server cron jobs over load?

I am not talking about the shitty wp-cron here.
Each for a plugin, I currently have four cron job tasks on my DirectAdmin/cPanel set at these intervals:

Every 1 minute
Every 2 minutes
Every 3 minutes
Every 5 minutes

A rough idea about my server spec:
Inode: 74770/∞
Bandwidth: 1.6GB/1 TB
2.71/10GB disk space (which is why I have integrated Amazon S3 for file offloading)

Do you think my cronjob settings is an overkill? What do you recommend?

Depends what each cronjob does (how many resources does it use) and if it has time to complete that job between that time frame.