BloodRage: Vcore fluctuating between load and idle

[saaya]

Some of you reported that vcore was fluctuating when the cpu was under partial load or switching from idle to load. This is a result of intel adjusting the VID of the Nehalem family processors on the fly. To prevent this from happening just disable CxE under CPU features in the QuantumBios menu.
Our engineers also recommend to ENABLE vdroop which should actually stabilize vcore.

If you want to use EIST to save power in idle, thats still going to work :)

Hope that helps! :toast:

[saaya]

Id like to add a comment about droop and the voltage reading hype:
many people dont like droop since they think a flat voltage rail is ideal, while i dont know all that much about electrical engineering myself, all engineers i talked to about this strongly disagree and explain that without droop any pwm will try to keep the voltage stable so hard, that the voltage will overshoot and undershoot for fractions of a second which hurts the chip and the pwm. So please check if vdroop really impacts your stability at overclocked speeds.

voltage monitoring is not nearly as accurate as many people think it is, those hardware monitor chips are designed to give an idea of the current voltages and idle/load changes, but are not meant, and are not, reliable enough to conclude if a voltage is stable or not. just because some software tool shows you a flat line when reading a voltage on your board or vga, it doesnt mean the voltage is in fact stable. this is valid the other way around too, if there are fluctuations on the reported voltages it doesnt necessarily mean the voltage is actually fluctuating. If you really want to know what your voltage is at and whether its stable, use a DMM and meassure as close to the chip that gets fed as possible. And dont forget, in the end what matters is if your system is stable and if you can reach a nice overclock. One board might have a lower and less stable voltage than another, or at least it might seem so, but it clocks better and is more stable at high speeds. which do you prefer? a board with seamingly clean and stable voltages or a board that overclocks well and runs stable? :D

[Raja@ASUS]

Good posts Sascha. I've noticed a number of boards that are optimized for use with Vdroop. Disabling Vdroop effectively screws the way the controller was designed to work. With no Vdroop, such boards actually ramp VCC under load (which is not good).

[tripgood]

Good posts Sascha. I've noticed a number of boards that are optimized for use with Vdroop. Disabling Vdroop effectively screws the way the controller was designed to work. With no Vdroop, such boards actually ramp VCC under load (which is not good).

So, where do you rate BR? Optimized for Vdroop enabled or disabled?

[Raja@ASUS]

The BR is optimized for use with Vdroop as are all DFI boards using the Volterra solution (that info is direct from the board engineers btw, Sascha above and the DFI stuff direct from Oskar). Best transient response and settling time on such boards comes from having Vdroop enabled.

later
Raja

[tripgood]

The BR is optimized for use with Vdroop as are all DFI boards using the Volterra solution (that info is direct from the board engineers btw, Sascha above and the DFI stuff direct from Oskar). Best transient response and settling time on such boards comes from having Vdroop enabled.

later
Raja

Thanks,
I have been running 3d stable (games) with vdroop enabled @206 bclk with no crashes or problems and that meets my definition for stability. I managed this with 2 different 3841A... chips. Waiting for DO stepping!:D

[Mescalamba]

I should read this before.. I dont get one thing.. why I'm warned in BIOS to not use it??! If its good? (it helps a lot, especially in OC)

[MagicBox]

I'm a bit confused by this as well: the setting is called "Enable Vdroop compensation" and would seem to suggest that enabling this setting actually disablesVdroop from happening. Is that a correct assumption? Thus, enabling Vdroop means having to disable this setting, disabling Vdroop having to enable this setting?