Parallels always running on MacBook Pro?

[RDAR]

is it safe to always have parallels running incase I have to use a windows program so it opens right away? will it have an effect on the CPU or RAM if its always on. I mean like this picture here, where I can just access like a little start menu on the top and run windows programs whenever I want without waiting for parallels to open up

 

[FHayek]

I believe you can configure Parallels not to use any Windows resources when idle. I keep P8 & Win 7 open all the time and often shows that I'm not eating any of my CPU power.