Best to use UEFI or Bios

Help needed on which firmware to use on my MSI Z87-GD65 gaming board. Is it better to use UEFI or the Legacy Bios and will I need to re-install windows 10?

UEFI gives you many more options generally speaking and in a GUI interface. Windows does not care which you use. The BIOS and UEFI are below the OS level.

If you have a more specific question fire away.

Thanks for the reply don256us
I was asking for better control on overclocking my cpu and graphics. I have changed it now to UEFI and going to see about the OC.

Doesn't MSI use the "Overclocker Genie"? I have a few MSI boards with that feature but I have yet to use it. One board is in my folding farm and I don't OC due to extra heat build up. The other board is one that I am still building for my future main rig and I have not played with OC yet on it.

For graphics OC'ing, almost everyone uses MSI's "Afterburner" program within Windows. It will allow you to up voltages and multiplier while also monitoring temps and fan speed in real time.

I'll try "Afterburner" tomorrow and see what I get. Not tried the Genie yet either, must give it ago. I'll see what others are getting on the MSI forum.
Just stripped my old water cooled rig down for a good clean down and possible upgrade.
Might get it set to do some folding if I can keep the noise down