Dual-boot Win7 Pro and Win10 Pro question

Hi guys...it's been a long time since I installed an OS so I wanted to ask first:
Is it best to install Win10 on a separate partition on the same SSD that Win7 is on? Or put Win10 on a separate SSD?

This desktop is old. I put it together in 2010 - MSI BigBang X58, Gulftown 980X, GTX 780 6GB, 24GB G.Skill. The Win10 upgrade didn't flag any hardware so I assume Win10 will run fine. Current OS is Win7 Pro 64-bit. I want to install Win10 Pro, then be able to choose which OS I use for that session w/out going into the BIOS every time. I have OEM DVDs for both OS.

I guess that's it - same SSD or separate SSDs - hopefully I can figure out the rest.
Thank you folks!

I should've been clearer - I'm trying to learn if there's any advantage to keeping the OS on separate drives - other than if a drive dies it doesn't take both OS with it.

I'd prefer to keep them on 2 different drives but is there a way to make both appear as a choice w/out going into the BIOS?

What SIW2 said. On Linux, you would use the Grub Menu, but on Windows Easy BCD seems to be the only way. There is a free version, at the bottom of the page:

EasyBCD - NeoSmart Technologies

rcanino said:

is there a way to make both appear as a choice w/out going into the BIOS?

Happens automatically. Just don't remove any disk.

Thank you for the replies!