Vdroop on Core 2 processors a "Feature"?

[AmongTheChosenX]

i ran across this anandtech article. Apparently Vdroop is a "feature" that protects the processor from over voltage.

But when I set my Voltage Damper on my E2180/Asus p5K-E, (CPU Voltage on Auto, 300 FSB) to disabled, the system crashes.

so basically it cannot get enough power because of Vdroop.

so it seems to be an actual "problem" for me, unless I need to work with voltages more.

but is itreally a feature? it puzzles me.

 

[WhiteZero]

When your turn off the dampener, is the vcore at stock or pumped up?
If it's turned up, and the PC does not work properly, one could conclude your overvolting.

 

[AmongTheChosenX]

When your turn off the dampener, is the vcore at stock or pumped up?
If it's turned up, and the PC does not work properly, one could conclude your overvolting.

the whole computer kept crashing for some reason, so heres waht i did.

Previous OC:

333 x 10 FSB x Multiplier
1:1 memory divider
1.5125 Volts

Current OC:

300 x 10 FSX x Multiplier
5:4 Memory Divider
Stock Voltage


so no I didn't over volt it because the board wouldn't do that unless I told it to.

 

[AmongTheChosenX]

anyone?

 

[Igthorn]

Yes, vdroop is a planned effect. According to what I've read it's there to reduce the cost of motherboards. Vdroop is used to deal with the current jumps when the processor goes from idle to load and load to idle with lower cost components. Supposedly it would cost more to have no vdroop and not burn out the voltage reg circuits. So we have vdroop and volt regs circuits that won't fry for less money.

(now I could be wrong and just misread everything)

Vdroop lowers voltage on load. So with voltage dampener off your processor is dropping below what it requires to stay stable at 300x10. Increase voltage or turn voltage dampener back on.

Vdroop also annoys overclockers

 

[Scali2]

I believe all Asus boards automatically overvolt the CPU when you overclock on 'auto' settings.
I know my P5B Deluxe does, and I've seen some others that do this aswell.

So you are probably not running the CPU at stock voltage, but at pretty high voltage, causing problems.
I know my CPU got a LOT of voltage when I ran 333 FSB.
So I manually set all voltage settings to stock, and then it ran much cooler at 333 FSB.

 

[Atech]

Yes, vdroop is a planned effect. According to what I've read it's there to reduce the cost of motherboards. Vdroop is used to deal with the current jumps when the processor goes from idle to load and load to idle with lower cost components. Supposedly it would cost more to have no vdroop and not burn out the voltage reg circuits. So we have vdroop and volt regs circuits that won't fry for less money.

(now I could be wrong and just misread everything)

Vdroop lowers voltage on load. So with voltage dampener off your processor is dropping below what it requires to stay stable at 300x10. Increase voltage or turn voltage dampener back on.

Vdroop also annoys overclockers

More about Vdroop and Voffset can be found here:
http://www.anandtech.com/cpuchipsets/intel/showdoc.aspx?i=3184

 

[Tazman2]

I believe all Asus boards automatically overvolt the CPU when you overclock on 'auto' settings.
I know my P5B Deluxe does, and I've seen some others that do this aswell.

Indeed. My eVGA does too. Found out by mistake when i noticed my temps sky rocketing and checked the bios and was very about it a day or two after i put the setup together. YIKES!

 

[jyi786]

Since it is impossible for the VRM to instantaneously adjust the voltage settings of the CPU on idle/load/idle cycles, the Vdroop is necessary to prevent voltage spikes that would otherwise destroy the CPU or the VRM.

Have a look here:
http://www.anandtech.com/cpuchipsets/intel/showdoc.aspx?i=3184&p=5

Incidentally, I have disabled Vdroop on my system and it runs just more cool/stable as it does without.

Edit: Damn. Atech beat me to it.

 

[AmongTheChosenX]

Alright i took a dive and decided to work with the Vdroop.

I orginally had the voltage dampener on in my P5K-E BIOS. I got the FSB to 333 x 10 Multiplier, at 1.5125 volts.
Idle temps were abput 25-28C, Load was 50-55C, 56 Peak.

I then decided to try and work with the Vdroop after reading that anandtech
so i disabled the dampener and heres what i got.

fastest OC so far is the following:

400 x 8x Multiplier, 3.2ghz (yes i lost 130mhz), at voltage in the BIOS of 1.4375.
Now because of the Vdroop, heres how windows reacts to the voltage.
Idle voltage stays about the same. 1.42-1.44 or so.
LOAD VOLTAGES, however had DECREASED DRASTICALLY!
when running undfer load, the computer has a CPU Voltage of:
1.4 VCORE!

And because the Vcore has gone so low, my temps have gone lower too!
New temps:
Idle, 23-27C
Load: 42-43, NEVER HIGHER than 45C
3.2Ghz

so basically me working with Vdroop got me 11C lower temps (though I sacrificed 130 mhz), and TONS more stability.
Also, with the Voltage Dampener on, I wasn't able to get the FSB to run at 400, it just would not do it. If it did on rare occassion, it ran for about 15 mins in windows and crashed Vista.

And I'm pretty sure that If I set the voltage to about 1.5, I can get it to run at like 3.4 or higher. with lower temps too!

Interesting. just thought I'd tell you guys.

 

[jyi786]

I guess I'm a bit confused.

I thought that the function of the Vdroop dampener was not only to prevent the Vdroop from happening, but to prevent the voltage from increasing to past what you set. I think this is probably misinformation that is caused by Asus's description of the function itself, according to different sources I've read across the web.

 

[AmongTheChosenX]

ah crap the 400FSB isn't stable.


i think its related to the BIOS though. Not the processor or its Vdroop.

 

[Manny Calavera]

I woudlnt think of turning off the Vdroop dampener on my mobo.It helps my oc greatly.