all vmod for all 6800

[vortex240]

reject - my bfg 6800oc idles at 50 load 58 thats already after I put AS5 on the core and somewhat lapped the heatsink

bilabong - your card could be a slow overclocker becuase of a simplified pcb design for an LE (8 pipes right?) by putting the caps on it you just make it like a stock 6800 vanilla, your black screen could be becuase of a shady powersupply

my card runs at 1.4v after a bios mod but artifacts above 385, in less shader demandng games I can run it at 405 ok...at 1.5v I can run it ok at 415 but its way to hot around the votage regulator area and I get black dots on screen sometimes

but funny thing is it never crashes even at 445 just artifacts so I'd say bilabong look into that powersupply maybe

I'm gonna wait to see those pics of the vdd mod firts until I do mine just to be 100% sure

happy new year

[Jethro]

anyone know the GPU voltage measuring points for a 6800NU?

[Del Gro Badeu]

core voltage measuring point are between Gnd and TP 11

[zadah]

I have modded two cards now:
Card 1:
before, 400/900Mhz added 2*3300uF caps to TP1 Now running 430/1000 Mhz, but this has only (8x1,6) pipes working... but pretty good increase...
getting about 9000 pts. in 3dMArk03
Card 2:
before, 400/700Mhz and black screen in most of the newest games (like HL2)
added 1x3000 uF cap to TP1 and 1*3000 uF soldered paraller to the "core" caps, they are those 2,5V /1500 uF caps on lower part of the card.
now running 430/800 Mhz without any Black screens and with 16x1,6 pipes..
getting 11250 points in 3dmark03

Ps. You should not solder any caps between TP11 and GND because TP11 is not directly connencted to Core rail..... YOu should only solder those extra caps directly to the pins of core capasitors....

[Del Gro Badeu]

nice increase, do you think we can do other mods to overclock 6800 / 6800 LE better than that ?

[zadah]

Well... if you want to do some extreme mods.... You could double your cards MOSFETSs, i think it would be quite easy, you would just solder the extra MOSFETs over existing ones (just little bit care on soldering)

Here is the parts
2 Upper gate mosfets
http://ec.irf.com/v6/en/US/adirect/i...ueryName=f7832

and 2 Lower Gate MOSFETS
http://ec.irf.com/v6/en/US/adirect/i...ueryName=f7821

But if you want do something easier you could only try bigger capasitors like 10000 uF... I think it is the cheapest and most safe

[stealthbomber]

YOu should only solder those extra caps directly to the pins of core capasitors....

Are you talking about the missing cap on the front of the PCB (where all the other caps are located), would soldering a 4700 uF cap back on help?

I ran out of variable pots so used a 1M pot instead, means I have to turn the pots in very small increments, still need to buy the caps... :banana4:

[Del Gro Badeu]

i think the most important 6800 NU / LE mods are done actually , thanks zadah for your help. Only need to write a beautiful guide with alot of pics in first post now

I will search for 6800 GT / U now. I've already contacted Volterra to obtain datasheet of VR1103M if someone with some electronic basis and a GF 6800 GT ( or Ultra ) is interested in this mod, post a reply

[Szymek]

so none of the above mods work on GTs ?

i've got leadtek 6800gt and willing to perform vmem mod

[zadah]

No , I dont mean the missing cap, i havent measured for what it was used to..

For improving yor DDRs overclockabilty put cap between points TP1 and GND
and if want do some soldering , you can add extra cap for your core allso...
Picture:
LINK

[Del Gro Badeu]

so none of the above mods work on GTs ?

i've got leadtek 6800gt and willing to perform vmem mod

only need to have access to the datasheet of the voltage regulator. If all goes normally, I will have it in few days ... but normally

zadah : I think i will use your pics for a global view of mods in a first time, after i will add some close-up pics but i haven't enough battery actually it isn't a problem to use your pics ?

[zadah]

zadah : I think i will use your pics for a global view of mods in a first time, after i will add some close-up pics but i haven't enough battery actually it isn't a problem to use your pics ?

Those arent my pics either i found them somewhere, You can use them if you want there wasnt any copyright information , I dont think anyone would care...

[stealthbomber]

No , I dont mean the missing cap, i havent measured for what it was used to..

For improving yor DDRs overclockabilty put cap between points TP1 and GND
and if want do some soldering , you can add extra cap for your core allso...
Picture:
LINK

Ahh cheers, I'm gonna try pick up some suitable 4700 uF 16v/35v caps tomorrow for the two mods, the space clearly marked on the PCB for the missing cap should be safe to add another 4700 uF cap there I assume.

Just hope the initial charge required for 3 additional 4700 uF caps don't kill the board...

[vortex240]

zadah did you change the core voltage when you moded the 2 cards?

Also did you have artifacts above 400 core before modding/adding the cap for the core? My core artifacts above 385, I never get black screens. I added a 3300uF cap parallel to the core cap; however, this did not allow me to oc any further.

[zadah]

zadah did you change the core voltage when you moded the 2 cards?

Ok, I have over volted cards to 1,5 V and 1,4 V, that is what you can do with NIBITOR v1.9

If you have proper cooling, you can put that 1,5 V BIOS to your card.... I think that would improve yor OC capabilities....

I had artifacts on 410/790 Mhz before mod and when using stock voltages (1,1-1,2 V)

[vortex240]

zadah I would not recomend 1.5v...I do have more then enough cooling for the core with 1.5v temps at load were 62c and 54 idle; however, the components regulating the voltage and the part with wraped around copper wire on it(front of the card by the caps) would reach easily 80-90c ...thats asking for a fried card in only a matter of time.

btw I used nibitor as well to mod my bios to 1.4v, 385 is the max at that setting

[reject]

my card runs nice at 410/600 now, i would be willing to try a cap mod
but i might put on some better air cooling that i have, or phase cooling

[stealthbomber]

zadah I would not recomend 1.5v...I do have more then enough cooling for the core with 1.5v temps at load were 62c and 54 idle; however, the components regulating the voltage and the part with wraped around copper wire on it(front of the card by the caps) would reach easily 80-90c ...thats asking for a fried card in only a matter of time.

btw I used nibitor as well to mod my bios to 1.4v, 385 is the max at that setting

I have the GPU running 425MHz @1.5v also, you need something like a Vantec spectrum card cooler that sucks air directly up onto the card.

As for the caps getting too hot, if they are decent quality caps then it should be rated to 105C max, however mines rarely "feel" that hot even after a few hours at load, adding the caps suggested by zadah should in theory help lower the temps at the back of the PCB.

[vortex240]

I have the GPU running 425MHz @1.5v also, you need something like a Vantec spectrum card cooler that sucks air directly up onto the card.

As for the caps getting too hot, if they are decent quality caps then it should be rated to 105C max, however mines rarely "feel" that hot even after a few hours at load, adding the caps suggested by zadah should in theory help lower the temps at the back of the PCB.

its not the caps, its the voltage controller chip, the part with copper wirer wrapped around it and some mosfets but this is compleatly up to the person wether or not they wanna take a chance...personally I cant afford another one of these

[stealthbomber]

Yes I see what your concern is now, a search over at nvnews.net shows many people with the same problem, their 6800LE/NU/GT cards failing only after 3 months when the GPU voltage is set to around 1.5v.

I've got some tiny heatsinks fitted onto my motherboards MOSFET's and they do a good job lowering the temps, I think I might try getting something like these: http://www.sidewindercomputers.com/misimoch.html

[Jethro]

for some reason my EVGA 6800nu handles even up to 1.6v with ease where a BFG6800GT didnt handle squat! Cooling the mosfets did help the BFG become more stable with volts but still not 100% in my case and that was watercooled!


The EVGA with 1.5v 16/6 i get 12406

Can someone show me where the TP11 is on this pic? Its my card and someone else's suggestions for reading vgpu.

[Bilabong]

Sounds like a good idea cooling the mosfets!

Gonna hacksaw an old cpu heatsink tommorow and use some heatpads. Do you think its worth cooling any of the other chips? maybe the V reg chip for mem/gpu/3.3V ref??

Bila

[Jethro]

Ok card is definatly at 1.6v via bios mod! ICS's are rather warm tho!

[stealthbomber]

Like I said a week before, pics of the mod provided, there are three 4700 uF 16v caps used (one located under the fan), initial tests show a 100MHz increase on the memory, this crappy Q-Tec PSU is due to be replaced very soon with far better 12v rails so until then...

[Szymek]

stealthbomber - what geforce 6800 brand you've got ?