GIGABYTE Radeon HD 7870 Windforce3 Voltage Mod?

I have bought two packs of these for MOSFET cooling
http://www.ebay.co.uk/itm/Copper-DD...1389744872176338067&pid=100033&prg=1032&rk=1&

and some of this to attach them.

http://www.ebay.co.uk/itm/Artic-Sil...hermal_Compounds_Supplies&hash=item2a14fd967a

I've never used the artic silver thermal adhesive, i have heard that it doesnt like to come off to easily.

I've been using akasa thermal tape. Its kinda costly but its got great thermal performance. Sticks well. That and in situations where you need a tiny bit of thickness its just about perfect.

http://www.frozencpu.com/products/7...x_80_mm_Square_AK-TT12-80.html?tl=g8c487s1291

You can probably find some from a place local to you.

Ok I will find somewhere to purchase that. On gpuz I get 2 voltages for VRM, based off the previous pictures. Where are the VRMs on my board as they get hot. Is that the units with R30 on top of them or the metal chokes? Also want to cool them.

The things with R30 are the inductors (chokes, coils, whatever), the little flat jobbies nearby with eight pins are the MOSFETs.

Ok. Do the chips with renesas on them also need cooling? As that's the area where most of the heat seems to be when the card is working.

the rensas square chips are the mosfets which are the heart of vrm's on this setup. the high and low mosfets are all part of that square rensas chip. Unlike other setups where they are seperate. The chokes dont really need to be cooled.

The rensas chips are core voltage vrm, the two pairs of mosfets on the right side of the card are memory and memory pll vrms i believe.

Hi,

So i'm close to conclusion with this mod.

On card 1 i was able to do 1330mhz core and 1370mhz memory @ 1.3v, temps would not go above 71c on burn in.

On card 2 i have to use 1.36v to get 1255mhz core and 1370mhz memory with temps hitting 90c.

They are both exactly the same model cards and are only 2 digits apart in serial number although i do believe that maybe card 2 has a less tolerant GPU.
Card 1 has a stock voltage of 1.168 and card 2 has a stock voltage of 1.218 which is a little odd.

I have backed off to 1220mhz core and 1350mhz memory @ crossfire, seems to be ok at this, although i am having difficulty getting Crysis2 to use the 2nd card in my crossfire setup.

This is what i'm going to settle for.

http://www.3dmark.com/3dm11/4154428
http://www.techpowerup.com/gpuz/hvwzd/
http://valid.canardpc.com/show_oc.php?id=2481291

If only my second card was as flexible as my first card i reckon i could break 16k.
But i'm still happy with the mod as i could not run Crysis stable with a 1220mhz core before, now i can.

Now we just have to work with you so you know how to take it cold. Then the real fun begins

TsunamiJuan said:

Now we just have to work with you so you know how to take it cold. Then the real fun begins

Click to expand...

I'm game for that :-D

Bobnova said:

The things with R30 are the inductors (chokes, coils, whatever), the little flat jobbies nearby with eight pins are the MOSFETs.

Click to expand...

Hello dear friend

I'm sorry to disturb you.

I need to participate in a contest on an Asus Radeon HD 7870 DirectCU II graphics hardware I Vmod ...

But the OCP and PLL voltage'm stuck and I need help ...

If you have information about this, please "gave me.

This information card :

http://lab501.ro/placi-video/amd-radeon-hd-7870-studiu-de-overclocking/7


Regards morteza

Here are my best guesses, I don't have one of those cards to actually test them on, so I don't know for sure.

First up, OCP. I'm fairly certain on this one:

(Example: Resistance across the capacitor is 10 ohms. Solder a 20 ohm resistor over it to raise the load required to trip OCP by 30-50%. Or solder a 10 ohm resistor over it to double the load required to trip OCP.
Do not short circuit them, one of the MOSFETs will almost certainly explode.
I would start with soldering a resistor on that is at least double the current resistance, if you raise the OCP trigger point too much a MOSFET will die.


Next, PLL. Mostly certain on this one, sorry it's vague. Without a higher res / better quality picture of this area of the card I can't do any better.

If the resistance to GND is lower than 3-4 ohms, you're going to need to swap the resistor that goes from that pin to vPLL with a resistor that is higher resistance.


Last is memory, though you may already have this under control:

not threadjackin, but should these diagrams work on a 7850? i have a MSI and am thinking of vModding it.

If it's reference, most likely.