Nvidia 8800GTS Vmods

[SF3D]

Vddr mod:
Original voltage 1.81V
Solder vr from red point to ground. Tune down to increase voltage. With 5 Kohm vr voltage will be 1,86V


Vgpu mod:
Original voltage 1.26V idle 1.21V load..weird
Connect variable resistor from red point to ground. Tune down and voltage will raise.


This one really work 1.3V 690MHZ (Aircooled)



Enjoy

[SF3D]

Result before mods (1.26V) 660/1880.
3DMark06 (10838)


Results after mods (1.3V) 690/1920

[afireinside]

I'm seeing 3 red points for the vgpu... Which ones?

[SF3D]

edit..

[afireinside]

Thanks Did you try the mods yet your self? I might give them a shot tomorrow but I'm already loading 66c on the stock cooler.

[doom_st]

mods are for water or at least serious air cooling...

SF3D you are the man...

i run out of vrs !!! Going to buy some and post later the results

[doom_st]

i have done vgpu mod
where is the measure point of vgpu?

edit: i think it doesn't work

[SF3D]

Read points:


I can confirm that Vmem mod works. GTX Vmem is 1.95V, so that should be safe.

I will check vgpu mod later today.

[doom_st]

i also tried read point from gtx . They work

1 used 1kohm vr for vgpu but nothing happens when i turn it. gpu always ~1.26

[SF3D]

Just tested VGpu mod myself. It works. I used 1Kohm vr.

Measure resistance between wires soldered on pcb. When you go below 47 ohm you will see that voltage raise. I tested 44.8 ohm and it gives 1.275V. Now my core can go over 670MHz, which was barrier before.

More voltage and results later

I think 1.3V-1.35V is more than enough with aircooling. With 1.275V idle is 58 c and load 77 c

[doom_st]

ok i'll check it maybe my vr is defective

[Orion24]

With 1.275V idle is 58 c and load 77 c

It's high for my taste. And I'll get a GTX that will go even higher. Liquid cooling is the way to go, but finding a waterblock that fits is a problem. The 2 I have in my 7900GTs now certainly don't fit .

[doom_st]

same i checked everything...

i read ~48 ohm from the wires soldered to the red points, solder the vr then nothing WTF?????????????

[SF3D]

You can do calculation here:
http://hyperphysics.phy-astr.gsu.edu.../dcex3.html#c1

[doom_st]

what make is your card?
mine is albatron
can you post a pic of you card moded?

[SF3D]

My card is ASUS. Every GTS are identical.

Maybe mod pics later.

[doom_st]

i replaced the 1kohm one with a new 100 ohm
no change at vgpu always ~1.26v

[doom_st]

have anyone else done vgpu mod?????????????????????????????
post if it works or not

[afireinside]

Under 47 ohm so wouldn't it be better to use something like an 80 or 100 ohm VR for more precision? All I have here is 10k.

[SF3D]

First post edited. I was pointing wrong resistor
irev210 send great pics and I was able to see traces properly.

SORRY about confusion.

Mod is easy. Just connect vr from red point to ground and that's it

My core can do 665MHz with 1.26V and now it can do 690MHz with 1.3V.
Previously 670MHz always locked up. Little more voltage, little more MHz

3DMark06 result in first post.

[SF3D]

Mod:


Idle 1.35V is higher than load ? Weird card..


Load 1.3V

[irev210]

First post edited. I was pointing wrong resistor
irev210 send great pics and I was able to see traces properly.

Glad i could help

[doom_st]

it works now

[Cupcake]

Nice job guys

im getting my GTS probably in the next week (or whenever I get paid for the mobo I sold)

[charlie]

nicely laid out, thx!