7900GT Voltmod-2

ryankenn, i actually PM'ed t024484 about that...

But this would have me shorting Point A to a point right next to it, AND then to ground. Most of the mods I've seen only go from Point A to ground, and aren't shorting to the pins next to it. I'm assuming it will work either way, just curious.

when looking here:
http://img87.imageshack.us/my.php?im...y8ei7sh3no.jpg

Looping over B is done to get 1,4v. If you also hit B then you get 1,50v. Doing only the "purple" line wont do anything. You need A to hit the groundpoint for 1,4v.


Dinho, OVP is in the ISL chip. If the chip dictates 1,2v, the ovp will kick in at 1,3v. But if you change the ISL chip to 1,4v, then the OVP will kick in at 1,50. Same if you go with 1,55v, OVP will be at 1,65. By modding the ISL chip table you simply bypass the ovp by making it output a higher default current.
Did you do the "resistor k" mod? (see post 1 and 2).

Quote:

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Originally Posted by illuminati-hwt

ryankenn, i actually PM'ed t024484 about that...

But this would have me shorting Point A to a point right next to it, AND then to ground. Most of the mods I've seen only go from Point A to ground, and aren't shorting to the pins next to it. I'm assuming it will work either way, just curious.

when looking here:
http://img87.imageshack.us/my.php?im...y8ei7sh3no.jpg

Looping over B is done to get 1,4v. If you also hit B then you get 1,50v. Doing only the "purple" line wont do anything. You need A to hit the groundpoint for 1,4v.



Dinho, OVP is in the ISL chip. If the chip dictates 1,2v, the ovp will kick in at 1,3v. But if you change the ISL chip to 1,4v, then the OVP will kick in at 1,50. Same if you go with 1,55v, OVP will be at 1,65. By modding the ISL chip table you simply bypass the ovp by making it output a higher default current.
Did you do the "resistor k" mod? (see post 1 and 2).

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Thanks,

Do you know offhand if the straight line across the bottom is good for 1.55V? From your second part of the post it sounds like going up to 1.55V like this would require me to also alter the OVP table?

Will the attached picture work on a 7900GT as well????

Deimos has it listed under GTX. But on this wesite: http://sg.vr-zone.com/print.php?i=3330 it shows the instructions under the GT section.



-----------------------
All you need is conductive paint. Copper or silver, make sure it's 100%. I reccomend CircuitWriter http://store.caig.com/s.nl/sc.2/category.174/.f
First remove the resistor marked above and replace it with a 50K ohms resistor. This will give you 1.5v for VGPU.

If more voltage is desired, I suggest you move onto step 2: removing the 2 resistors marked to disable overcurrent protection for the card.

You can then move onto step 3: Soldering and connecting this point to any grounded spot. This will give you 1.6v.

Instead of step3, you can do step 4 if 1.7v is required.

Found on:
http://www.xtremesystems.org/forums/...&postcount=188



Many have done it at xtreme:
http://www.xtremesystems.org/forums/...t=92874&page=8

User Powerstrip to OC:
http://www.entechtaiwan.com/util/ps.shtm

Nvidia 7900GT compared to other graphics cards:
http://sg.vr-zone.com/?i=3335

Details @ VR Zone: http://www.vr-zone.com/print.php?i=3437
Power Consumption/Heat Output/Chart
Geforce 7900GT @ Default voltage/Speed 64 watts
Geforce 7900GT @ 745MHz 1.5v 87 watts
Geforce 7900GT @ 780MHz 1.6v 101 watts
Geforce 7900GT @ 800MHz 1.7v 111 watts

Anyone getting a high pitched whine after doing the gpu volt mod? I'm hearing it as the 3D acceleration kicks in only...not sure if it's an issue with the regulator or ?

I want to to the 1.4V with the conductive pen, but I cant find any store here in Iceland which sells conductive pens.. Can I use a pencil? or solder between those points?

Quote:

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Dinho, OVP is in the ISL chip. If the chip dictates 1,2v, the ovp will kick in at 1,3v. But if you change the ISL chip to 1,4v, then the OVP will kick in at 1,50. Same if you go with 1,55v, OVP will be at 1,65. By modding the ISL chip table you simply bypass the ovp by making it output a higher default current.
Did you do the "resistor k" mod? (see post 1 and 2).

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I change the J resistor from 5K to 50K to get 1.5V then mod the resistor K to 45K.
Try to 1.6V but still tops 695.

no mods yet. allready got 14k on 05 :D without an sli bridge
card's is up at 550/1800 with the pci-e frequency at 115mhz.
gonna play a little more with the pci-e frequency. still got stock coolers, so carnt realy mod yet, though im itching to.
i think on my chiller, i should be looking at 700+ core each :)

Quote:

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Originally Posted by ST4

Anyone getting a high pitched whine after doing the gpu volt mod? I'm hearing it as the 3D acceleration kicks in only...not sure if it's an issue with the regulator or ?

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I have that issue with the card @ stock, I think it is a coil vibrating that causes the noise, some hot-glue or nail polish should take care of that... Have not bothered to look at which component causes it though... Simply poking around with a ziptie or rubber something should help you identify the source easily...

Quote:

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Originally Posted by ryankenn

Thanks,

Do you know offhand if the straight line across the bottom is good for 1.55V? From your second part of the post it sounds like going up to 1.55V like this would require me to also alter the OVP table?

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I would like to ask the same question...

Does this work?:confused:

i have done the 1.4 volt mod.
Now i want to try the 1.55 mod. :rolleyes:

The blu line represents my actual mod

http://img388.imageshack.us/img388/5737/provamod9oq.jpg

I soldered the two points, I didn't use a pencil or silver paint.

To get 1.55v do i have to change the second soldered point from 511 to 508 (from the blu line to the yellow line?) Or I have to solder the 511 AND the 508 point?

And I also want to increase the memory voltage from 2.02 to 2.22

I tried whit a pencil but it doesn't work

Can i solder the 2 points whitout resistor? like the picture

http://img220.imageshack.us/img220/645/memorymod8jh.jpg

Thank you :woot: :woot:

Ok, I have a question about the resistor that controlls the switching freq, labeled K in the first post. Has it been determined that this is necessary, or ony necessary on some cards or not at all?

My card came stock at 450/660, it would overclock 580/900 on stock volts.

As of right now, i'm up to 1.5 volts on the core which gives me 724/921 and can run benchmarks with ease. I've also changed the delta from 20 that was stock, up to 40 in the bios. So far i'm happy with my results, but I just wonder if this K resistor could be holding me back some.

Do you guys think its worth it to pull the water block off and go through all the trouble of soldering a 100K resistor in parallel with this one? Or just leave it as it is.

Also, how much more could I get out of the card if I go ahead and mod to 1.55v on the core?


Thanks,


Marlon

Quote:

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Originally Posted by iL .PoLLo

i have done the 1.4 volt mod.
Now i want to try the 1.55 mod. :rolleyes:

The blu line represents my actual mod

I tried whit a pencil but it doesn't work

Can i solder the 2 points whitout resistor? like the picture

Thank you :woot: :woot:

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You have already posted this exact same question in another thread, please DO NOT cross post :nono: :slapass:

hm... can any1 post something about this strange "clock/too high --> resetting to defaults" behavior?

i mean:
"
I have increased the freq from 540 to 610, showing bizzarre behaviors: arctifacting, a little hesitation, some 3DMark crashes and after it run without arctifact.
Does nVidia driver roll back to lower frequencies if you pushed it too much?
"

WTF? Can anyone write anythink about it?

Quote:

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Originally Posted by snakeskinner

Ok, I have a question about the resistor that controlls the switching freq, labeled K in the first post. Has it been determined that this is necessary, or ony necessary on some cards or not at all?

My card came stock at 450/660, it would overclock 580/900 on stock volts.

As of right now, i'm up to 1.5 volts on the core which gives me 724/921 and can run benchmarks with ease. I've also changed the delta from 20 that was stock, up to 40 in the bios. So far i'm happy with my results, but I just wonder if this K resistor could be holding me back some.

Do you guys think its worth it to pull the water block off and go through all the trouble of soldering a 100K resistor in parallel with this one? Or just leave it as it is.

Also, how much more could I get out of the card if I go ahead and mod to 1.55v on the core?


Thanks,


Marlon

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If all you have done ist to raise Vcore to 1.5Volt, with the result that you have now 724/921, I would advise you to leave all the other suggestions for what they are.
You have a golden 7900GT, and you better be careful with it.
Obviously your power supply can still handle the increased current demand, so forget the 100Kohm.

Going from 1.5 to 1.55 Volt will not give you a dramatic increase either, expect something like 10 to 20 Mhz, on the other hand your Core will demand more power so depending on how close to the edge you already are, it could also mean that you will have no gain at all or even worse.

Quote:

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Originally Posted by qba_dx

hm... can any1 post something about this strange "clock/too high --> resetting to defaults" behavior?

i mean:
"
I have increased the freq from 540 to 610, showing bizzarre behaviors: arctifacting, a little hesitation, some 3DMark crashes and after it run without arctifact.
Does nVidia driver roll back to lower frequencies if you pushed it too much?
"

WTF? Can anyone write anythink about it?

---

You do not mention at all wether you have done any modding at all, so it is difficult to answer your question.
Going to 610Mhz without modding is certainly asking for trouble.
Nvidia does not roll back anything at all, but I suppose you have installed Coolbits to give you a higher clock.
In that case you can indicate wether you want to have the higher clock setting at startup. if not set, the clock will go to its settings stored in the Bios at start up.

t024484; in my experience the nVidia driver does indeed roll back the overclock when it somehow thinks it is unstable, I've seen it a few times myself on my 7900...

Though what causes it to actually roll back I have no clue about... The only way I notice it is that my FPS in the testprogram all of a sudden drop to stock speed...

OK, heres mine. A little sloppy but you get the idea.

Here is my experience.

I have a XFX 7900GT Extreme Edition 520/1500 (default speed)

I did the "easy volt" mod (ink) and the switching frequency mod (pencil). It took 15 minutes to perform both mods.

I swapped the heatsink to a Zalman VF700cu. (The stock heat sink is loud and hot running)

I run my Zalman at the slowest possible speed and it is completely quiet. Not bad for a top of the line graphics card. I hate fan noise!

As a comparison:
The Stock fan temperature was 52c idle and 83c during load. = LOUD
The Zalman at the slowest possible speed, 49c idle and 68 during load. = quiet


1.20 volt, max overclock: 540/1770
1.40 volt, max overclock: 645/1770
1.45 volt, max overclock: 662/1770
1.50 volt, max overclock: 682/1770
1.55 volt, max overclock: I haven’t tried it yet. But it looks like 700Mhz is possible.

I really have no need to push it further since my AMD 64 3200+ CPU is a total bottle neck. I ran a 3dmark05 with 7900GTX speed settings (650/1600). It scored 9603 3dmark05 points. A 4400+ X2 probably would have scored 10,500 to 11,000 points.

By the way. I paid $309 including shipping at ZipZoomfly.com

Quote:

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Originally Posted by Haltech

OK, heres mine. A little sloppy but you get the idea.

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Haltech, it was either the upper or the lower trace. You did both.
It doesn´t do any harm, so leave it as it is.
P.S. Nice picture that you made.

Quote:

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Originally Posted by t024484

If all you have done ist to raise Vcore to 1.5Volt, with the result that you have now 724/921, I would advise you to leave all the other suggestions for what they are.
You have a golden 7900GT, and you better be careful with it.
Obviously your power supply can still handle the increased current demand, so forget the 100Kohm.

Going from 1.5 to 1.55 Volt will not give you a dramatic increase either, expect something like 10 to 20 Mhz, on the other hand your Core will demand more power so depending on how close to the edge you already are, it could also mean that you will have no gain at all or even worse.

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Cool, thanks for the reply. I don't know how I got so lucky to get a great card, nothing else I've ever got was a great overclocker. But this is a really good one, so i'll just leave it alone and enjoy its performance for a while.


Marlon

Quote:

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Originally Posted by t024484

Haltech, it was either the upper or the lower trace. You did both.
It doesn´t do any harm, so leave it as it is.
P.S. Nice picture that you made.

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Yea I realized that like when the original thread was started Failsafe mods never hurt lol.

Quote:

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Originally Posted by Haltech

Yea I realized that like when the original thread was started Failsafe mods never hurt lol.

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Thanks for posting that, I've asked about the single lower line getting to 1.55V and hadn't heard of anyone who had tried it. I've got my conductive goop and Thermalright V1 just sitting here waiting for that picture.

Nice!

Ryan:woot:

I've just installed my Zalman VF900cu and painted the single bottom line (1.55v) All worked well.:banana: Optimal nVidia settings came back with 659core and 784mem. Does that sound like 1.55v? I'm sure I could get much higher with powerstrips.
Just thought I'd say thanks for the great thread!:toast:

Quote:

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Originally Posted by beta67

I've just installed my Zalman VF900cu and painted the single bottom line (1.55v) All worked well.:banana: Optimal nVidia settings came back with 659core and 784mem. Does that sound like 1.55v? I'm sure I could get much higher with powerstrips.
Just thought I'd say thanks for the great thread!:toast:

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What temps are you getting?

/Grau

I'm getting 36 now and 42ish on a heavy load. Having big probs with flickering in games. :( Turned the overclocking off and it still flickers. It's not my cpu or the pci-e slot. Anyone had this prob or have any ideas?? Ta
Mike