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GeForce 8800 GS/GT/GTS Voltmods

Discussion in 'Articles' started by largon, Feb 28, 2008.

  1. largon New Member

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    Last edited by a moderator: Feb 29, 2008
  2. infrared New Member

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    Thanks largon, very useful article indeed.
  3. warhammer New Member

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    Nice article Largon, what benefits would this mod give me. I can push my GPU to 780 with no probs.
  4. largon New Member

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    warhammer,
    780MHz at stock vGPU is really nice indeed, vGPU mod would allow you to push it well past 800MHz and with the right voltage I bet 900MHz could be gaming stable - assuming your card(s) are under water as well...
    Shader clocks gain from vGPU too.
    albinowino and warhammer say thanks.
  5. wolf

    wolf Performance Enthusiast

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    at 1.3vcore+ i hit OCP, so im keeping it under that atm, max benchable freeq's are 840/2052 core/shader. at around 1.3v, atm i run my old oc (760/1836) jsut with 1.2v as it was not completely stable before and loves some extra juice.

    weird thing is i get the very low volume high pitch whine/buzz that other 8800GT owners have talked about, it did this the first day i got it with no o/c's and doesnt seem to effect system stability....should i remove all mods and RMA?
  6. warhammer New Member

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    Thank you for the explenation largon.
  7. largon New Member

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    To be sure it's OCP that's limiting you measure the vGPU after the screen goes blank. When OCP activates vGPU goes to ~0v.
    The buzzing is nothing to be worried about. It's the vGPU coils that start resonating at high frequencies.
  8. wolf

    wolf Performance Enthusiast

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    so no need to RMA at all? no sweat? cos i am a little worried....
  9. largon New Member

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    No worries, the coils that cause the buzzing are just simple coils of copper wire, they are pretty much indestructible so resonating will not hurt the card or the components. The buzz can be irritating though. :\

    Pretty much all high-powered video cards do it anyways...
    wolf says thanks.
  10. wolf

    wolf Performance Enthusiast

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    cheers man you are an absolute legend, for the article, the advice .... jsut cheers man :D
  11. candle_86 New Member

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    my GS has yet to buzz
  12. infrared New Member

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    Get a really quiet system, and turn the fan down on the card and i can pretty much guarantee that you'll hear a faint high pitch squeel when you open the 3d veiw in atitool. It's just that some cards are slightly louder than others.
  13. albinowino

    albinowino New Member

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    First I must say this article is awesome and makes it all much simpler than reading through the massive XSF thread, thanks for taking the time to write it. I am wondering about the reverse VMem page however. From what I gather, this mod decreases voltage as resistance is lowered so to have the pot set up for CCW turns lowering the voltage, the pot needs to be wired differently. Do I have it right?
  14. largon New Member

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    albinowino,
    That's right. Anyways, I edited the pics for vMEM and Reverse_vMEM according to voltage change and tuning direction.
    :)
    Last edited: Mar 7, 2008
    albinowino says thanks.
  15. albinowino

    albinowino New Member

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    Excellent! BTW I like the renditions of the wires and pots. So much easier on the eyes than dots :D I'll be trying the VMem pencil mod to see if my GT responds to more VMem. Stock is 1.88v strangely.
  16. Titus

    Titus New Member

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    Great thanks Largon :respect::respect::respect:

    Nice thread ! I own a 8800 GS and i touch the limits wiyh it suddenly : i think i can push it more but not without a V-mod. I will take my soldering iron and follow your directives after a bios flashing test @ max actual stable frequencies.

    :nutkick:
  17. gOJDO New Member

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    Very good Largon! :toast:

    But what about the Pencil/BIOS mods?

    /me is making a custom water block but has no balls to do a hard mod on his GTS. :nutkick:
  18. largon New Member

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    Pencil mod is not possible, and IMO the only BIOS mod worth mentioning would be a GDDR3 timing-tweak if you got the dreaded Qimonda onboard.
  19. Titus

    Titus New Member

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    If someone has an idea for a GDDR3 timing-tweak for Qimonda chips for my XFX 8800 GS bios modded :rolleyes:
  20. nflesher87

    nflesher87 Staff

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    any recommendations on where best to purchase a soldering iron and resistors?
    I have a DMM I can borrow from the physics department here at school :)
  21. phyx1u5 New Member

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    Hi there,
    Just a query with the reverse volt mod, do you set the resistance of the resistor to minimal then turn up the resistance? or start at 50k ohms and turn down the resistance?
    Also is a 1k ohm VR ok for the vgpu mod? Im not planning to exceed 1.35volts loaded
    Cheers
  22. largon New Member

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    Always set the VR to maximum resistance. And yes, 1kΩ is perfectly good for vGPU mod.
  23. Laurijan

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    Thanks lagron for this thread and the one at xtremesystems..
  24. largon New Member

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    Cheers!
    :)
  25. Dar_T New Member

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    Hey largon, so I have my cards at 1.38v but every time I try to join a game in Cod4 it will use the over current protection on me. I was sort of unclear as to how to fix it in your OP. Since I have 8800 GTS and 3 points do I use two resistors? Which type of resistors (ohms).

    Thanks

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