BIOS Features
The BIOS on the XFX nForce 680i motherboard looks VERY much identical to past 680i motherboards, but it’s worth another look here for first timers.
This is the menu in which all the magic happens!
Somehow I think this might be a bit optimistic, but apparently you can set a 60x multiplier using our engineering sample QX6850 processor!
The PCI Express bus can be overclocked from the default 100 MHz speeds up to 200 MHz.
The bus speeds between the two chips of the 680i SLI chipset is standard at 200 MHz but overclocking it is possible as well; up to 500 MHz.
The actual bus speeds menu in the XFX BIOS is where the most interesting features are found, including the SLI memory options. Above the setting is at “CPUOC 0%” which basically tells the BIOS you want the fastest SLI memory speed it can give you without overclocking the processor at all. You can see the the BIOS is going to run our memory at 1142 MHz in this configuration.
Setting it to “Disable” allows you to manually control all the settings yourself. The memory would run at 800 MHz by default here until we manually change it.
By setting the CPU to maximum overclock, the SLI memory settings would actually still remain at 1142 MHz — obviously the BIOS is timid when it comes to overclocking our new quad-core 1333 MHz FSB processors.
In manual mode, you can set the memory clocks to Auto, Linked or Unlinked. Unlinked allows you to set the memory speeds completely independently of the FSB speed while linked creates a ratio relationship between the two speeds.
Here we can set the FSB of the motherboard anywhere from 400 MHz up to 2500 MHz. These FSB settings are in the fact the resulting quad-pumped FSB, so a setting of 1700 MHz will actually be 1700 MHz unlike in some other motherboard BIOS settings where you would set it at 400 MHz for a resulting 1600 MHz FSB.
With the unlinked mode, you can set the memory speeds to up to 1400 MHz as well.
For the linked mode you can select one of the above ratios to set the relationship between the FSB and memory speed, or set it to Sync mode where the BIOS again has more control over the speeds.
I love the memory timings page here because of the dual columns that indicate what the current settings of the BIOS are and what you are attempting to change it to.
The two most prominent memory timings are the CAS latency and Command Rate settings shown above.
