On the motherboards BIOS page the earliest BIOS is 'P8H61-M LX R2.0 BIOS 0304'.
To run the newer Ivy Bridge processors you will need to update the BIOS to at least 'P8H61-M LX R2.0 BIOS 0308'.
Bios 0308 is quite an old BIOS and there are much newer BIOS versions on the page.
I suggest upgrading the newest stable BIOS 'P8H61-M LX R2.0 BIOS 1204' if you want to use the 3570/3470.
https://www.asus.com/Motherboards/P8H61M_LX_R20/HelpDesk_Download/
Be aware though that flashing to a new BIOS is generally safe; however if performed incorrectly can end up bricking the board.
Make sure you flash the BIOS as described on the ASUS support page with a USB in the motherboard BIOS.
To find your current BIOS I suggest downloading CPU-Z and...