EVGA 680i - Vdroop Mod?

[jokester]

I've got my 680i and QX6700 Prime Stable as 3.6GHz using 1.575V in the BIOS, this droops to about 1.475V with all four cores fully loaded with temps about 70C (on water). Now I can live with that as it'll rarely see that sort of loads in normal use.

The problem is though that the Vdroop increases with the number of fully loaded cores. So the problem I've got is that with one core at 100% the droop is only down to 1.515-1.52 which means with only one core loaded it reaches 70C as well.

Anyone know of a Vdroop mod such that I can set it to 1.475 or thereabout and not have to worry about higher voltages when idling/light use?

Thanks,

Jokester

[easyrider]

I too would be interested in any solution to the 680i droop issue.

[celemine1Gig]

I've got my 680i and QX6700 Prime Stable as 3.6GHz using 1.575V in the BIOS, this droops to about 1.475V with all four cores fully loaded with temps about 70C (on water). Now I can live with that as it'll rarely see that sort of loads in normal use.

The problem is though that the Vdroop increases with the number of fully loaded cores. So the problem I've got is that with one core at 100% the droop is only down to 1.515-1.52 which means with only one core loaded it reaches 70C as well.

That is absolutely normal and the function of droop anyway. The more current is drawn, the higher the droop. The more cores are loaded, the more current. That's it. It's there to take some strain off of the circuit and to be able to further reduce the costs.

Here's a nice link:

http://www.maxim-ic.com/appnotes.cfm/appnote_number/993

Anyone know of a Vdroop mod such that I can set it to 1.475 or thereabout and not have to worry about higher voltages when idling/light use?

Thanks,

Jokester

If you want to be able to reduce the Droop voltage, you'll have to tell what vcore controller your particular motherboard uses.

[quent]

Agreed, and btw please take an high-res photograph of the controller zone.

Regards

[jokester]

http://premium1.uploadit.org/jokester//680i.JPG (1MB)

Think that's it there, I'm no expert but I think it's that ADP3189 chip on the right. That the right one?

Jokester

[quent]

Please check resistance between pins 16 and 17.

Regards

[jokester]

Pin to pin resistance is about 12K.

Jokester

[Kabauterman]

this is not a Droop on Nvidia 680i Board

it is Undervolting, the Droop is around 0.02 V (realy OK for QuadCore) but the Board Undervols very hard to 0.08 V

I have the same config and you only must set 0,8 V more then you will have

[jokester]

I'm under the impression that undervolting is what you get at idle, but droop is what you get on load, for the reasons that celemine1Gig gives. My last Vdroop mod on a P5W, not only got rid of the droop on a Conroe, but actually increased Vcore whilst under load.

Jokester

[Kabauterman]

I mean the same the board Undervolts 0.08 V at idle and the droop at load is 0.02 V

but the droop is very good vor QX6700

the Bad Axe 2 and Abit AW9D-Max have a droop of 0.04 V

[jokester]

With 1.575V in the BIOS I'm getting:-

Idle ~1.525V
1 load ~1.505V
2 load ~1.49V
3 load ~1.48V
4 load ~1.47V

What I want to do, is minimise the difference between idle and full load voltages, to reduce temps when only 1 core is maxed out.

Jokester

[easyrider]

Does anyone know of a mod the tackles the limited FSB issues with the 680i and the quad cores?

[celemine1Gig]

Connect a 200K (~6% resistance decrease) or a 500K (~2% resistance decrease) trimmer potentiometer, set to the maximum resistance, between pin 16 and 17. Trim the resistance down to decrease vdroop.

[jokester]

Thanks, looks like it's going to be have to be done to a new board though, this current one's RAID controller has just failed again (despite flashing to P23).

Jokester

[jokester]

Any idea what happens if I just soldered those two pins together? Will it
just do away with droop altogether or will it go up in smoke?

Jokester

[celemine1Gig]

Any idea what happens if I just soldered those two pins together? Will it
just do away with droop altogether or will it go up in smoke?

Jokester

You'll cause a short circuit, so the latter of your stated options will probably happen.