all vmod for all 6800

[OnLine]

There is one big problem with this mod on 6800le...and i dont recommend to use this

If you put this power supply in pareller with your 6800le, you are going to give extra stress to the cards own lower gate MOSFETS, because they are short Circuited!!!!! when using this mod.... and I think they are going to warm a lot.....

The problems is that card is using PWM regulator and that mod is using Linear regulator... and they dont work together... In PWM regulation Mosfets are switching on/off in high duty cycle and In linear regulation (LM317) transistor is on all the time.

If you want to make volt mod, you sholud replase cards mosfets to bigger ones or put similar MOSFETs paraller with the existing ones., I have tried this (because i have burnt UGATE MOSFET of my own 6800le)

Aha, so don't use this mod whenever MOSFETs are used.
6800LE's users, don't do this mod !

What about 6800NU's, do they use MOSFETs ?

[OnLine]

Eek! I think I fried my 6800 GT with the vmem mod.

What mem mod ?

This one ;


And what happened ?

[stealthbomber]

Most (if not all) 6800LE/NU PCB's and it's components are identical AFAIK, only the bios and pipeline bridge configurations (resistors found at the back of the PCB) are different.

[kryptobs2000]

yeah, that one lol. I made another thread, I'll post the link

http://www.xtremesystems.org/forums/...ad.php?t=50933

there ya go, hopefully it's fixable but I'm not getting a good feeling. Maybe it's rma-able

[OnLine]

Most (if not all) 6800LE/NU PCB's and it's components are identical AFAIK, only the bios and pipeline bridge configurations (resistors found at the back of the PCB) are different.

Yeah I thought so,

6800LE's/NU's users don't do the power mod !

Instead, to boost the power supplyed to the core and/or mem You should probably do like zadah said; replace the MOSFETs "with bigger ones or put similar MOSFETs paraller with the existing ones".

[LardArse]

yeah, that one lol. I made another thread, I'll post the link

http://www.xtremesystems.org/forums/...ad.php?t=50933

there ya go, hopefully it's fixable but I'm not getting a good feeling. Maybe it's rma-able

How could the mod have killed it if its just one end soldered, its totally not in affecting the circuit at all.

[kryptobs2000]

Not sure, not trying to hi jack this thread, I made another. I think it might have been in contact with that metal er... dot, to the upper left of the resistor (see the pic in my thread).

[zadah]

Aha, so don't use this mod whenever MOSFETs are used.
6800LE's users, don't do this mod !

What about 6800NU's, do they use MOSFETs ?

I think all of the 6800 series cards are using PWM regulators!!! so using this mod is very risky.... you should use it only without cards own regulator running.

I have tested to run 6800 LE:s core voltage with only one 1,5V AA Battery, works fine , But you have to disable PWM regulation... (And the regular AA Battery doesnt last very long about 5-10 minutes , so this mod is not for gaming )

I tried this battery mod after i Fried UGATE MOSFET of the card.

[acdc]

Hi everyone,
I've read the vmem voltage mod guide for 6800GT/Ultra in VR-Zone, but i have some notes and I'd like to warn 6800 ultra's users - Don't make this mod because it will easily damage the memory! This guide is right for only 6800GT, but not for 6800Ulta, because its memory is made with different (from 6800GT) power distributions. Nvidia set for ultra 2x Voltera's VT223 PWM chips (in contrast to 6800GT where there is only one - the second is missing) but their outputs don't share power! Every PWM distrubute power for two pairs of memory chips - half of the memory. I don't know what's reason NVIDIA engineers to set separate power in pair, because one of Voltera's VT223 basic features is to connect two or more chips in shared outputs as master and slave to distribute more power.
For the right mod of ultra, it is necessary to change resistanse of two resistors (in contrast to GT where there is only one and its see in the VR-Zone guide) with the same value - 43KOhm for 6800U reference design. Each of this resistors determines the voltage for 2 pairs of mem chips, and for this reason there will be two check points - in contrast to the 6800GT where there is one checkpoint because only one PWM Voltera's VT223 is set and it distributes power for all memory chips.
I have eVGA 6800 Limited Edition (The same PCB and components that Ultra), but for me this mod makes the memory unstable. I don't know why it happens, but i think it is due to a problem in the distribution of the proper Vref (Vref=0.7Vddq) that DDR3 requires.
In the pictures below you can see the second resistor marked in violet, and the check points are in the same colors as the resistors.

[OnLine]

I think all of the 6800 series cards are using PWM regulators!!! so using this mod is very risky.... you should use it only without cards own regulator running.

I have tested to run 6800 LE:s core voltage with only one 1,5V AA Battery, works fine , But you have to disable PWM regulation... (And the regular AA Battery doesnt last very long about 5-10 minutes , so this mod is not for gaming )

I tried this battery mod after i Fried UGATE MOSFET of the card.

6800gt/u is very different from le/nu and doesn't have any MOSFETs.
Using this mod on my GT is no problem, the thing is when this mod is connected to the board the heatsink [ see pic ] which cools a part [ 3 BGA styled chips, 2 fore core 1 for mem ] of the power regulator gets cooler.

Edit: 3 Voltera's PWM chips [ ty acdc ], that's what the heatsinks cool AFAIK.

The card doesn't behave or anything and no part of the board is hot.
The core voltage is close to rock stable.



Ha ha, 1,5V AA Battery that's awesome but good to know if You lose the electricity to the house.

Edit: how can I disable the cards own regulator ?

Edit: and do You have an idea where or if I should add more caps in order to make the power supplyed to the board/core more stable.

[LardArse]

Hi everyone,
I've read the vmem voltage mod guide for 6800GT/Ultra in VR-Zone, but i have some notes and I'd like to warn 6800 ultra's users - Don't make this mod because it will easily damage the memory! This guide is right for only 6800GT, but not for 6800Ulta, because its memory is made with different (from 6800GT) power distributions. Nvidia set for ultra 2x Voltera's VT223 PWM chips (in contrast to 6800GT where there is only one - the second is missing) but their outputs don't share power! Every PWM distrubute power for two pairs of memory chips - half of the memory. I don't know what's reason NVIDIA engineers to set separate power in pair, because one of Voltera's VT223 basic features is to connect two or more chips in shared outputs as master and slave to distribute more power.
For the right mod of ultra, it is necessary to change resistanse of two resistors (in contrast to GT where there is only one and its see in the VR-Zone guide) with the same value - 43KOhm for 6800U reference design. Each of this resistors determines the voltage for 2 pairs of mem chips, and for this reason there will be two check points - in contrast to the 6800GT where there is one checkpoint because only one PWM Voltera's VT223 is set and it distributes power for all memory chips.
I have eVGA 6800 Limited Edition (The same PCB and components that Ultra), but for me this mod makes the memory unstable. I don't know why it happens, but i think it is due to a problem in the distribution of the proper Vref (Vref=0.7Vddq) that DDR3 requires.
In the pictures below you can see the second resistor marked in violet, and the check points are in the same colors as the resistors.

Good info there, but it does help on the 6800U we tried it on, just penciling that resistor. It was an Inno3D.

[Del Gro Badeu]

hum, i've a lot of difficulty to get a clean HQ photography of my unmodded GF 6800
if someone could do this for me it will be really nice.

post it here and i will add it to the quick how to i'm currently writing for the firs post

[kryptobs2000]

Is it a GT or a regular 6800?

[stealthbomber]

Can't do it, my cheap 4 year old Fuji 2.1MP digicam is useless in closeup macro mode, although I'm sure a decent pro photographer will manage something a bit more acceptable in macro mode...

[zadah]

6800gt/u is very different from le/nu and doesn't have any MOSFETs.
Using this mod on my GT is no problem, the thing is when this mod is connected to the board the heatsink [ see pic ] which cools a part [ 3 BGA styled chips, 2 fore core 1 for mem ] of the power regulator gets cooler.

Edit: 3 Voltera's PWM chips [ ty acdc ], that's what the heatsinks cool AFAIK.

I think the chips under the heatsink are the MOSFETS, because PWM control chip doesnt need any heatsink. If the heatsink is really getting colder, the extra mod can be used without any risk. In this case, PWM control is driving cards own MOSFETs down, beacause of over voltage in sensing line of the PWM control chip ( I am still sure, that every 6800 series card has PWM controlled MOSFETS, because other way is linear regulation, like LM317 in your mod.)

And Reason for Ultra cards distributing power to two different Memory lines is the fact that you cant use two PWM power supplies in the same power line.

Edit: how can I disable the cards own regulator ?

Edit: and do You have an idea where or if I should add more caps in order to make the power supplyed to the board/core more stable.

You seem to have disabled it allready , atleast it is not running in 100% power, if the heatsink is cooler. If you want to completely disable regultors you should ground the gate pins of all MOSFETS or remove them completely...
but i think there is no need for that in your case.

But if you want to make HEAVY DUTY supply replace MOSFETS with biggers ones like 30V/100A. Currently cards are using values like 20V/15-20 A...

I dont know if there is any help to use extra caps on GT/Ultra cards, because they seem to have power supplies, which deliver stable voltage on "stock" settings.

[OnLine]

I think the chips under the heatsink are the MOSFETS, because PWM control chip doesnt need any heatsink. If the heatsink is really getting colder, the extra mod can be used without any risk. In this case, PWM control is driving cards own MOSFETs down, beacause of over voltage in sensing line of the PWM control chip ( I am still sure, that every 6800 series card has PWM controlled MOSFETS, because other way is linear regulation, like LM317 in your mod.)

And Reason for Ultra cards distributing power to two different Memory lines is the fact that you cant use two PWM power supplies in the same power line.


You seem to have disabled it allready , atleast it is not running in 100% power, if the heatsink is cooler. If you want to completely disable regultors you should ground the gate pins of all MOSFETS or remove them completely...
but i think there is no need for that in your case.

But if you want to make HEAVY DUTY supply replace MOSFETS with biggers ones like 30V/100A. Currently cards are using values like 20V/15-20 A...

I dont know if there is any help to use extra caps on GT/Ultra cards, because they seem to have power supplies, which deliver stable voltage on "stock" settings.

Thank You !



Doesn't MOSFETs always look like that or similar ?
3 legs, black and big.

Under the heatsink, there are 3 tiny BGA styled chips [ grey IIRC and many legs ].
I'm confused now ?

[Jethro]

Has anyone come up with a pencil mod for the ram on 6800NU?> I just dont want to take my card out with the waterblock making such good contact.

also I have a naked dead 6800GT i can take pics of and post if needed.

[Del Gro Badeu]

Is it a GT or a regular 6800?

it's a regular 6800

Can't do it, my cheap 4 year old Fuji 2.1MP digicam is useless in closeup macro mode, although I'm sure a decent pro photographer will manage something a bit more acceptable in macro mode...

one of my friend's father is journalist and photographer and have a really good digicam ( a lot of MP ) i can ask for him to take some photography but it will take some extra days

[stealthbomber]

Has anyone come up with a pencil mod for the ram on 6800NU?> I just dont want to take my card out with the waterblock making such good contact.

also I have a naked dead 6800GT i can take pics of and post if needed.

It's a unnecessary risky mod to perform, things such as fixed resistance dependant on lead type used, quality of signal path (correct me if I'm wrong here) etc.. mods for the lazy people...

[Jethro]

Dang dood your anal! Some of the best clockers in the world dabble with pencil mods. Who the hell made you clocking GURu elite? Its not rocket science lol.

If i want to be "lazy" and Carefully raise my DDR voltage with a pencil mod to test it out and then if it amounts to anything install a POT later than so be it. what the hell is wrong with you?

[stealthbomber]

Dang dood your anal! Some of the best clockers in the world dabble with pencil mods. Who the hell made you clocking GURu elite? Its not rocket science lol.

If i want to be lazy and Carefully raise my DDR voltage with a pencil mod to test it out and then if it amounts to anything install a POT later than so be it. what the hell is wrong with you?

LOL

Just an opinion, it's an easy mod to perform but a "clean" permanent contact is preferred, take a chill pill would you!

[Jethro]

Ill take a chill pill if you stop being such an opinionated geek ok?



QUOTE:

It's a unnecessary risky mod to perform, things such as fixed resistance dependant on lead type used, quality of signal path (correct me if I'm wrong here) etc.. mods for the lazy people...


ALL the mods were doing are RISKY and unecessary and thats really besides the point. Pencil mods are no more risky than taking a soldiering iron to a $300 dollar board IMO. If you can measure resistance before and after than its really not very risky at all...

[stealthbomber]

Ill take a chill pill if you stop being such an opinionated geek ok?



QUOTE:

It's a unnecessary risky mod to perform, things such as fixed resistance dependant on lead type used, quality of signal path (correct me if I'm wrong here) etc.. mods for the lazy people...


ALL the mods were doing are RISKY and unecessary and thats really besides the point. Pencil mods are no more risky than taking a soldiering iron to a $300 dollar board IMO. If you can measure resistance before and after than its really not very risky at all...

That depends on your soldering skills and the way the mod is suppose to work, I'd take the advice of the EE's (with far more confidence) over any overclocking guru around (who usually has a fair bit of money to replace any fried hardware), any day.

[Jethro]

Im sorry maybe its a communication gap but i dont see the point of your last post to be honest dood.

Anyways back on topic, for thos who wish to know the GPU measuring point of the 6800NU

[firada]

There are someone to explain me how to do a success capmod at my card?I have msi nx6800le and i tried did the mod with 3300mf/16v but didn't worked!If are you can explain exactly(with photo it's fine)please post a reply to forum!Plss hellpp!Thnx