DFI's 680iLT board is based around the NV BIOS specifications that Nvidia laid out for the LT series boards. Award version 6 modular BIOS is used with the overclocking options located under the Genie BIOS menu.
FSB (QDR): 400MHz to 2500MHz in 1MHz increments
Memory (DDR): 400MHz to 1400MHz in 1MHz increments
PCIe Slot 1: 100MHz to 131MHz in 1MHz increments
PCIe Slot 2: 100MHz to 131MHz in 1MHz increments
SPP to MCP Reference Clock: 200MHz to 500MHz in various increments
CPU VID Control: 0.44350v to 1.60v in 0.025v increments
CPU Vcore Add: 100% to 121.25% in +.25% increments
DDR2 Voltage: 1.8v to 2.5v in 0.025v increments
NB Core: 1.31v to 1.76v in 0.03v increments
SB Core: 1.54v to 1.58v in 0.03v increments
SB Dual: 1.54v to 1.85v in various increments
LTD Voltage: 1.23v to 1.58v in various increments
CPU VTT Ref Voltage: 1.23v to 1.63v in various increments
With all these settings we managed to get a total FSB of 487MHz with DDR-2 voltage at 2.2v, NB Core at 1.56v, SB Core at 1.56v, LTD Voltage at 1.37v.
We are quite happy with this OC result as this board is not designed to go as high as the 680i SLI series but has managed to surprise us and it is shaping up to be quite a good product considering it is going to be cheaper than the high-end 680i SLI boards.
Important Editor Note: Our maximum overclocking result is the best result we managed in our limited time testing the motherboard. Due to time constraints we do not have enough time to tweak the motherboard to the maximum and find the highest possible FSB as this could take days to properly find. We do however spend at least a few hours overclocking every motherboard to try and find the highest possible overclock in that time frame. You may or may not be able to overclock higher if you spend more time tweaking or as new BIOS updates are released or "burn in" time might come into play if you believe in that.