FSB VTT Voltage - E6400 / MSI nf650i

What does this option do / it's in percentages - up to 20%.

Thanks.

High CPU voltages might become unstable, so instead of increasing the cpu voltage even more, you can increase this one instead.

On the Asus P5N-E SLI there is no such option, so I had to increase the voltage of the E4300 to 1.7v in order to be stable at 3.48ghz.

It is called Front Side Bus VolTage Termination

just so i understand this - if my CPU is semi-stable (say get the rounding error in superpiX2), then i should consider upping the FSB VTT before i consider upping the Vcore, and this is expected to do a similar job, but at the chipset level rather than the CPU level?

After considerable googling on the subject (I was interested as well):

CPU VTT is the most important setting for stable overclocks. The CPU VTT Voltage sets the CPU termination voltage, allowing for a 1.55V maximum. Using this voltage in combination with the CPU VCore voltage setting can greatly enhance the system stability while overclocked. The system memory reference voltage is split between settings, the controller reference voltage and one option each for the two memory channels. In all cases, the base reference voltage can be set to a maximum of .03V over half of the set memory voltage. (Taken from HardOCP)

"In summary, the CPU VTT controls the CPU termination voltage. Based on Kirmie's observations, it reduces the number of false electrical signals by providing a form of "ground" to pull out these false currents. ." (Credit to Kirmie for the find) My experience with this board is that the max setting (1.55) provides the best results. I have not had a single crash or temperature variation as a result.

source : http://www.overclock.net/intel-mothe...ing-guide.html

some more

http://www.thetechrepository.com/showthread.php?t=87

I was wondering what the usefulness of the FSB VTT was too. Looks like if you set it at max (20%), stability improves like crazy. To test that anyway, I've got my e6420 running at 437 x 8 = 3500Mhz with the RAM at some weird ratio to keep it at 800. Vcore is at 1.50, FSB VTT is at 20% (MSI P6N SLI-FI), NB Voltage at 1.45, SB at 1.6 and so far after 1 hour and 6 minutes of orthos (both cores at ~66C, overall cpu temp is 55C) no crashes and no errors =) Anybody else fiddle with the FSB VTT?