Usually outdated bios won't cause performance issues out of the blue. it's possible that it's the bios if you upgraded something in your computer and the current bios doesn't fully support that hardware, or if you have always had performance issues.
I checked the Gigabyte site and looked at the bios update descriptions for that motherboard and unless you have a hardware compatibility issue then it won't help to upgrade.
GIGABYTE - Motherboard - Socket 1366 - GA-X58A-UD7 (rev. 2.0)
When troubleshooting performance you need to think about what is not performing well, is it the entire computer from start up to surfing the internet or is it just loading programs.
If you can describe your problem in a little more detail I might be able to help more.