What version are you looking for?  What version are you at? You can find the older versions here (search page for 'r710'):[URL] 
We found a r710 in one of our  racks. It was registered in dhcp in 2010 but has never been turned on. I have read several posts pointing out problem in upgrading the r710 bios to 6.4 from very old versions. Could someone tell me where to download old version so we can do step upgrades?   
need old R710 bios