8800GTS 512Mb (G92) vMods

[K404]

Yea, been thinking about that. Still to test the pot placement. Might need to add in some insulation for the back of the card.

Good luck with the benching T_M I hope you get the MHz and results i think this card of capable of

[G-Man]

Is the OVP protection still kicking in at the same 1.35v as the GT? If not, What clocks are you all getting with 1.4v plus?

[Nosfer@tu]

I must have missed somthing, this is the first time i se 8880

[MorGo7h]

I must have missed somthing, this is the first time i se 8880

Prolly a mistake.

[T_M]

fixed

[syn7h37ic]

This is my result:
1.36 volt, GPU only.

[dinos22]

try running higher shaders as they impact performance a lot

[tranceaddict]

What is the stock voltage for the 8800 GTS/GT? Moreover, is there a BIOS volt mod for the GTS?

[Stelios]

What is the stock voltage for the 8800 GTS/GT? Moreover, is there a BIOS volt mod for the GTS?

1.15V stock voltage for GTS . No bios mod can give you higher vgpu.

[NiNe_iZe]

great work Tim !!

Thanks for this mod

[s e t h]

dont need to unsolder them, shorting them out with small pieces of wire will work Electricity is lazy- if it has a choice of a resistive path (resistor) or non-resistive path (bit of wire) it will skip the resistor totally. Thats assuming the wire has no resistance at all, which is only true in theory, but its "close enough" here.

worst case scenario: the wire and the resistor form a parallel resistive network, but the total equivalent resistance will basically be the resistance of the wire.

[/theory]

I hadnt looked at it until you pointed it out so...thanks for the heads up! Im hoping it wont be an issue, but every pushed back ceiling will help me.


@ Bala: Cheers bro! Are you all ready to bench as well?



big OT: I was gonna be benching tomorrow, but delayed it till Monday. I was hoping to be the first to publish frozen GTS clocking...I think il be beaten to it now!

please explain this to me a little more carefully...i really don't like obviously voiding my warranty and if what you say is correct then a simple stripe of conductive paint accross the top the the relevant resistors would achieve the same removal of OCP.
to my thinking removing the resister will not be the same as bridging it...removed the circuit should be broken due to connections literally missing and therefor almost infinate resistence in those circuits disables the OCP...however bridging the resisters with wire or paint will result in almost no resistence being offered and the circuits will remain intact...

so how is bridging the resisters anything like removing them?

please excuse if i've misunderstood the intricacies involved here as i have no electronic background whatsoever..

if anyone can work out how to disable OCP without voiding the warranty i'll be very pleased
(at this point i'm also not sure if these GTS512mb cards have the same capability in terms of removing OCP will allow LN2 voltages without further issue)

[T_M]

I too was confused by that comment.

[cowie]

so how is bridging the resisters anything like removing them?
its not two different things
remove no current at all
short 100 current floqw
so im lost on that comment as well

[The Asgard]

Glad it just isn't me but like everyone else I just about know enough to get by.

Shame really since I have a degree in electrical and electronic engineering.

[jason4207]

I think that if you decrease resistance by soldering another resistor (or Cu wire) in parallel you are raising the OCP threshold. OCP won't kick in until much higher current flows. If you get the right value resistor in there you can raise OCP, but still allow some level of protection (probably a good thing). Just soldering a Cu wire or using a conductive pen will raise the OCP threshold to a level where you probably will never have to worry about it anymore.

Removing the resistor completely removes OCP.

Both end up giving you the same result, but do it in different ways.

This is what I've gathered from all my readings on here and other forums as well some PMs w/ some very knowledgeable people. I also have a B.S. in Computer Engineering.

I don't know this to be fact, but it seems to make sense. In any case take it w/ a grain of salt.

[Timbosan]

I think that if you decrease resistance by soldering another resistor (or Cu wire) in parallel you are raising the OCP threshold. OCP won't kick in until much higher current flows. If you get the right value resistor in there you can raise OCP, but still allow some level of protection (probably a good thing). Just soldering a Cu wire or using a conductive pen will raise the OCP threshold to a level where you probably will never have to worry about it anymore.

Removing the resistor completely removes OCP.

Both end up giving you the same result, but do it in different ways.

This is what I've gathered from all my readings on here and other forums as well some PMs w/ some very knowledgeable people. I also have a B.S. in Computer Engineering.

I don't know this to be fact, but it seems to make sense. In any case take it w/ a grain of salt.

No stop confusing people. If you remove the resistor, the circuit is broken, and the primarion contoller never gets a signal from that circuit to trigger OCP so OCP is removed. If you short out the resistors, you would increase the signal the primarion controller gets, by lowering the resistance, and most likely lowering the OCP point. The card may not even boot. Do not bridge the resistors.

[NightRaven]

well one thing i thought of then..

would be grounding the ocp/ovp resistors.

however, the primarion might take it as infinite resistance or bridging the resistors since the circuit isnt broken.. only one way to find out

[s e t h]

simple pencil modding the relevant OCP resisters will reveal if lowering resistence raises OCP kick in point...easy and usefull experiment.

i too wondered about grounding the OCP resisters but then though better of it :p

good luck ... maybe we see some even more serious clocks from these cores pretty soon...like 1200mhz or more :0

thanks for publishing your sub0 results with these NightRaven
it seems serious 3D benching just reached a lower price point...always a good thing

[jason4207]

No stop confusing people. If you remove the resistor, the circuit is broken, and the primarion contoller never gets a signal from that circuit to trigger OCP so OCP is removed. If you short out the resistors, you would increase the signal the primarion controller gets, by lowering the resistance, and most likely lowering the OCP point. The card may not even boot. Do not bridge the resistors.

I heard from a very good source that soldering resistors in parallel (lowering resistance) would raise the OCP threshold. He specifically mentioned 4.2-4.7k for the 2 locations on the 8800GT. I'm assuming that bridging the connector would just raise the OCP threshold higher, and since someone posted that it worked for them it seemed logical.

Re-reading his email it seems that bridging is a bad idea after all as the regulator is also using that signal to keep the current sharing b/n the 2 phases in balance.

Soldering resistors in parallel seems to be the best way to gain more voltage headroom, and is the only way recommended to me by my source.

I do agree that removing the resistor will remove OCP, and I said that in my previous post.

Again I haven't tried any of this...yet, but I know my source has, and he confirmed the results.

My source: Viper John (thanks buddy!)

[Timbosan]

i may have been a little harsh, i just dont wanna see a post saying "i just bridged the resistors and burnt my card". Viper John does know his stuff, no question. However are you sure you arent confusing OCP with the OVP mod? In the OVP mod we decrease the resistance of a single resistor, to ~4.7k, as this increases the signal to which the real signal is compared thereby raising the over-voltage trigger point.
for this OCP mod, we are trying to decrease the signal sent to the primarion controller, rather than alter the signal to which it is compared, as we dont know how that system works exactly.

[jason4207]

I looked back again to confirm and he has the 4.2-4.7k resistors in parallel w/ the 2 brownish resistors b/n the 78x & the 15b resistors...not the 78x resistor itself. So you were good to call me on it, b/c otherwise mis-information may have spread.

This mod will reduce the amount of voltage drop the OCP sees by ~25%.

This is the OCP, not OVP mod that I'm referring to, but it is on the 8800GT, not the 8800GTS-512 mentioned in the thread title. I'm sure the mods will be similar, though. The GTS-512 has 3-phase power, so I'm not sure how that affects it yet. I'm still learning!

Sorry for the confusion!

[T_M]

can a mod please move this GT talk to another thread?

[jason4207]

Sorry if I seemed OT, but it seems to me that a mod for the GT will be relevant to finding a working mod for the GTS-512.

If soldering the 2 resistors in parallel as I described works on the GT, then it would seem logical to assume that doing something similar on the 3 resistors on the GTS-512 would work as well.



The values on the GT were 4.2-4.7k, and I'd think similar values on the GTS-512 might work, but since the GTS-512 has a higher working voltage then a different value may be in order.

I'll leave it to you experts to figure out the values if I'm on the right track. Or maybe I'll hit up VJ and see if he's had time to play w/ this card yet.

Sorry if I pissed anyone off. I just got my GTS-512 yesterday, and I just wanted to see this card get tweaked before I took my soldering iron to it (this will be my 1st vmod on a gfx card). I thought I had some info that might help you guys reverse engineer this thing. I'm sorry if I mislead anyone or posted any mis-information.

[jenqho]

[QUOTE=jason4207;2638524]I looked back again to confirm and he has the 4.2-4.7k resistors in parallel w/ the 2 brownish resistors b/n the 78x & the 15b resistors...not the 78x resistor itself. So you were good to call me on it, b/c otherwise mis-information may have spread.

Are you sure the 2 brownsih components are "Resistors"?? They looks like SMT capacitors to me.

[jason4207]

Sorry again! Yes those components are SMC's, not SMR's.