p35c-ds3r -ISL6327 -vcore &vdrop tech question

[messerchmidt]

hey all,

been trying to figure out how-to work a vcore and vdroop mod for my p35c-ds3r as no one else seems to have done it yet...(should have gotten a p35-ds3r instead...)

i read the guide at vr-zone for figuring out your own vmods, so i am going to try.

The p35 series from gigabyte uses the ISL6327 Enhanced 6-Phase PWM Controller with 8-Bit VID Code and Differential Inductor DCR or Resistor Current Sensing. I found the specs online in .pdf format.

http://www.intersil.com/data/fn/fn9276.pdf

I cannot figure out the v-droop mod, but i think that I got the vcore down.

As for vcore, am i right in soldering a 500kohm VR to the 0 resistance point coming from the fb leg of the ISL6327, and connecting it to ground for a vcore mod? can someone confirm?


what do i look for to do the v-droop mod? what pin from the ISL6327 do I follow? FB or VSEN or?!?!



thanks

[messerchmidt]

the red dot is the zero resistance point from FB pin

[Micutzu]

pin 15 to GND = Vcore adj
pin 17 to pin 15 = Vdroop adj

Measure the resistance from pin 17 to pin 15 first, it is very important in choosing the correct pots. Do not reduce the vdroop too much if you don't upgrade the PWM output capacitors otherwise you'll get instability.

PS: please use thumbnails next time, the image is too big.

[messerchmidt]

thanks

p.s. ok, next time wil use smaller pics

[messerchmidt]

hmm cannot figure it out. tried to do the vcore @ the red point on this pic, no luck. 500km vr to this point and to ground. did not tr vdroop b/c could not figure it out. hopefully someone will post pics for my board soon....



red is zero res from pin 15, green is zero res from 17.

[Micutzu]

What is the resitance from pin 15 to pin 17 ?

[messerchmidt]

2.27kohm (if I am not doing something wrong)

[messerchmidt]

I am using a 500k vr based on this: http://www.vr-zone.com/index.php?i=4966&s=10

[messerchmidt]

anyone?

[Micutzu]

Try a 25K-50K pot, it should be OK; 500k is way too much.

[El Snorro]

Does anyone has a final solution for the vcore en vdroop mod on the p35c??
I am searching it badly!

thnx

[Lestat]

Try a 25K-50K pot, it should be OK; 500k is way too much.

you do realise that a 500k POT isnt 500 all the time.
people keep saying this is too much or that is too much.

if you stick your meter on the damn thing and set it properly or set it to match the resistance hte baord uses already it is NOT too much.

they go from 0 - 500 k so tell me how its too much.
if he only needs a 50k pot then adjust the 500k to 50kohm and let it be.

i never understood why you people say that, a pot is ADJUSTABLE, thats why the largest pot in the world would work cuz you simply adjust it down to the resistance you desire.

i dont know maybe im just retarded about this stuff, i have said repeatedly that elctricity isnt my forte but its an adjustable pot ...
if its not an adjustable one, then its not a POT its just a resister, which puts out a solid 24/7 500k

[El Snorro]

you do realise that a 500k POT isnt 500 all the time.
people keep saying this is too much or that is too much.

if you stick your meter on the damn thing and set it properly or set it to match the resistance hte baord uses already it is NOT too much.

they go from 0 - 500 k so tell me how its too much.
if he only needs a 50k pot then adjust the 500k to 50kohm and let it be.

i never understood why you people say that, a pot is ADJUSTABLE, thats why the largest pot in the world would work cuz you simply adjust it down to the resistance you desire.

i dont know maybe im just retarded about this stuff, i have said repeatedly that elctricity isnt my forte but its an adjustable pot ...
if its not an adjustable one, then its not a POT its just a resister, which puts out a solid 24/7 500k

You don't have any tips for the vcore/vdroop mod itsself?

Thnx in advance!

[bassie]

you do realise that a 500k POT isnt 500 all the time.
people keep saying this is too much or that is too much.

if you stick your meter on the damn thing and set it properly or set it to match the resistance hte baord uses already it is NOT too much.

they go from 0 - 500 k so tell me how its too much.
if he only needs a 50k pot then adjust the 500k to 50kohm and let it be.

i never understood why you people say that, a pot is ADJUSTABLE, thats why the largest pot in the world would work cuz you simply adjust it down to the resistance you desire.

i dont know maybe im just retarded about this stuff, i have said repeatedly that elctricity isnt my forte but its an adjustable pot ...
if its not an adjustable one, then its not a POT its just a resister, which puts out a solid 24/7 500k

Its about precision i think. It is much easier to get 32kohm out of a 50kohm then out a 500kohm. With the right value it is much easier to set the right resistance.

edit:

Maybe that if you think you'll need 500kohm instead of 50kohm you twist a bit, but not far enough to get to 50kohm and nothing happens. So you'll probably think that the mod isnt working.

[K.I.T.T.]

Its about precision i think. It is much easier to get 32kohm out of a 50kohm then out a 500kohm. With the right value it is much easier to set the right resistance.

QFT

[El Snorro]

Anyone some tips about the vmod?

Thnx in advance!

[El Snorro]

Anyone?
I really need this vcore mod in order to use my mach2 properly!

[El Snorro]

Found the point, soldered a 50k Vr on it and the vcore mod works



Ni I only need the vdroop.
Anyone have tips?
Thnx in advance!!

[messerchmidt]

anyone figure out a vdroop mod for this board yet?

[celemine1Gig]

Micutzu already told you.

If the resistance between "VDIFF" and "FB" really is 2.27 K-Ohm, then connecting a 100K-Ohm potentiometer in parallel, set to its maximum resistance, should do the trick.

[messerchmidt]

so connect a 100k-ohm resistor between the two points, and no more vdroop, right? (excuse my electronic incompetence, I study accounting and finance...)

[celemine1Gig]

so connect a 100k-ohm resistor between the two points, and no more vdroop, right? (excuse my electronic incompetence, I study accounting and finance...)

You connect the potentiometer between pin#15 and pin#17, tuned to its full 100K resistance. Then when it's soldered in and the system is running, you adjust it downwards to eliminate vdroop (if needed).

As Micutzu also already said, if you really want to totally eliminate vdroop you'd have to increase the output capacitance. So don't set it to 0V vdroop, as it could give you instability issues.

[messerchmidt]

ok going to give it a try;

if someone did the mod already, and it worked, can they upload a picture?

[messerchmidt]

got a g0 stepping xeon 3210

going to put it in and try the mod on Wensday or Thursday, will report back then

anyone give it a try?