XFX 7900GX2 Vmod, need help!

Hi,

i have the 7900GX2 and really want to try a mod for Vgpu, but i don't know if the layout is compareable to any other nVidia card? So i tooked some pictures of the card, maybe some guys here can help me to find out the mod?! :toast:

There is this part on the right side on the back of the card:
http://www.gravedigga.de/gravedigga/gx2mod/gx2_mod.jpg

And on the left is this IC:
http://www.gravedigga.de/gravedigga/..._mod_dunno.jpg

Full view of the card:
http://www.gravedigga.de/gravedigga/...2_mod_full.jpg

Hope someone can help me and thx a lot in advance!

Regards

Edit: The layout looks a bit like the one from the 7900GTX, and it is the same IC (ISL 6534CRZ).

Full view of the card:
http://213.202.211.105/gravedigga/gx...2_mod_full.jpg

:eek: :eek:

That card is MASSIVE! WOW!

Yeah, it's really big! :)

The IC that is a bit cut off in first pic:
http://213.202.211.105/gravedigga/gx2mod/gx2ding.png

LOL WTH it's even longer than the 7950GX2. :O

One of the cracks here want to help me please? :)

Pleaaaase xs pimp my gx2! :p:

If i should mesure anything, just tell it to me, it is no problem! I will do almost everything to get this baby modded! :D

Vr-Zone has a guide on modding the GX2. Look there.

Thx, but it is for the 7950.

One more try.. Anyone? :)

First measure values from those resistor marked in picture. Then calculate size of variable resistors you are going to use. Measure voltages also, so you can see which voltage raise when you lower resistance :D

Intersil 6535crz: VGPU: That is REFIN method. Decrease resistance--> higher voltage.

Intersil 6549: VMEM. Decrease resistance--> higher voltage.

Attachment 53592

Wow! :toast:

Did u already used this Mod, or i'm teh first one to do it? :D

Thx a lot! :woot:

You might be first one :D, I don't have this card.

Good luck and report back if there is problems.

Ok, will give it a try soon, hopefully i do not damage the card.. :p:

Thx mate!

Ok, here are the values of the resitors.

http://666kb.com/i/ajvs0j83fd1nwbxu5.jpg

Which vr i should use for Vgpu? :)

Use 20Kohm vr. (Just to be sure)

This is easy tool to calculate vr values or something else.
http://hyperphysics.phy-astr.gsu.edu.../dcex3.html#c1

Thx. But just have 5K, 10K and 50K at home! :)

10K will be safe too? If not, i will use teh 50K and adjust it to 20K.

With 10Kohm, voltage sholudn't go much higher than default, but still try 50K first.

Thx!

Do u have any idea for a Vgpu messuring point? I tried this one*, but it do not worked. :)

*
http://666kb.com/i/ajxx2mecqawd5m36d.jpg

Edit: Hmm, my multimeter was broken.. *g*

Ok, the Vgpu mod u painted in is not really one! Vgpu stays on 1,27V but the picture on the screen is totally broken, a lot of artefacts.. Thank god that my card is working again, after i removed the VR! :p:

OK. :confused:
ISL 6534 must be Vmem then. (same vmem controller in 7900GTO)

Could you check this value?
Attachment 53734

Just the value from this red point to ground? :confused: I messured teh resistor in front of it before, and it was 3,8 mOhm. Will messure it. :)

Next thing. Which end is ground?

Attachment 53735

http://666kb.com/i/ajz5houqq36mbdahq.jpg

http://666kb.com/i/ajz5i3so6ua6l3eji.jpg

There shouldn't be any problem with these mods :confused:

Hmmm...there is two parts in this card. (Two separate pcb) Is that other pcb identical?

Quote:

---

Originally Posted by SF3D

Hmmm...there is two parts in this card. (Two separate pcb) Is that other pcb identical?

---

Yes, this part is identical.

But something is wrong. Hmm, stupid question but which pin on the vr is ground? Sorry, i'm out of the electronic part since years.. :(

Try to connect vr to mod points on both PCBs. Then measure resistance. Lower resistance very little first. Example 1070ohm -->1000ohm. (ISL 6534)

Then boot your computer and measure voltage. If you don't lower resistance much, there shouldn't be any problems.

I'm back! :)

Did the mods on ISL6534 today on both PCBs and started with a resistance of 1018ohm. No artefacts this time, but i lowered resitance to about 850ohm and i got no voltage gain from it, so i presume it is maybe the Vddr mod? Or should i lower the resitance more? But i stoped there, bcs. if it is for the Vddr i will damage it, without any measuring point..

Should i try the mod now on the other IC?

http://666kb.com/i/ajz5houqq36mbdahq.jpg

Thanks for your reply in advance! :toast:

What a small GPU :) Pf its HUGE!:eek: :eek: :eek: :eek:

The card has DDR3, correct?

Stick the black probe of your multimeter into a black wire of a molex (ground), and with the red probe carefully measure voltage on the larger tan colored resistors in the volt modding area. Look for around 1.8-1.9 volts for a memory read point.

Found the point for Vddr now and lowered resistance to about 850ohm again, but nothing happened on Vddr too?! :p: What mod i did there..

http://666kb.com/i/amrk5dba6a8t61pgr.jpg

1,920V on 1070ohm and 1,920V on 850ohm. :stick:

Ok, now Vddr works perfect on ISL6549CBZ, but i do not really need this mod. Please someone can recheck the mod for Vgpu on ISL6534CRZ?! :)

I already tried to understand it, by reading the specification papers from the IC, but i don't get it.. :(

Please guys! :clap:

Anyone want to help me plz?! :(