ATI 3850/3870 Voltmod thread

[Zannema]

i've 1 problem, my Club 3D 3870 is the OC edition and the circuit of voltage GPU generator is different.....where's the point for the vgpu's mod???



This is an image of the circuit (sorry for the quality), thank to all and sorry for disturbe

[Riska]

Here marked in green

[Zannema]

Thank Riska

[Cha0s]

So i did this pencil mod on R1222 for increasing vGPU ..
but more than 840Mhz will result in a hang in CSS

so i will try this hardware mod tomorrow.. if I could reach 1ghz GPU ,..it would be cool

my cooling is : Accelero S1 + 2x 92mm Cooler


should be enought cooling or not?

[eva2000]

Is this what you wanted? here is one of my modded cards, with v-core read point and a removable jumper for when I'm not benching.

http://img215.imageshack.us/img215/1...tmod026pi4.jpg

thanks but it seems my card backside is slightly different seems like a few more resistors exist on my than the reference ones - see http://i4memory.com/reviewimages/vid...IceQ3_007.html ?

[Menhir]

So i did this pencil mod on R1222 for increasing vGPU ..
but more than 840Mhz will result in a hang in CSS

so i will try this hardware mod tomorrow.. if I could reach 1ghz GPU ,..it would be cool

my cooling is : Accelero S1 + 2x 92mm Cooler


should be enought cooling or not?

what card and voltage do u have?

i've a 3850 512MB and use same AC S1 + Dual 92x92 Fans@12Volt
my gpu clock is 905Mhz and voltage 1.47volt
temp is max 60°C load

i think the cooling should be enough but i bet i will not reach 1Ghz gpu clock even with more than 1.5Volt

[Cha0s]

what card and voltage do u have?

i've a 3850 512MB and use same AC S1 + Dual 92x92 Fans@12Volt
my gpu clock is 905Mhz and voltage 1.47volt
temp is max 60°C load

i think the cooling should be enough but i bet i will not reach 1Ghz gpu clock even with more than 1.5Volt

Voltage now is about 1,38 with the pencil mod @HD3850 at 840Mhz core...
and thats not enought for me
ok 1000Mhz is not a "must have" but 900 should be reachable or not?
With 1,5v it should be,...?

and how did u mod it? with a variable resistor or even with the pencil mod`?

[Menhir]

Voltage now is about 1,38 with the pencil mod @HD3850 at 840Mhz core...
and thats not enought for me
ok 1000Mhz is not a "must have" but 900 should be reachable or not?
With 1,5v it should be,...?

and how did u mod it? with a variable resistor or even with the pencil mod`?

its never enough until the GPU is dead
the 900 should be possible for you

i modded it using pencil mod and fixed the mod using sticky tape that pencil is not blown away

[gurusan]

I can go all the way to 953mhz stable @ 1.5v, but to get to 1012mhz I require 1.6v!! I only crank it up that high for benching :p

These new ATI cards seem to love the volts, even the 3870s

[Cha0s]

its never enough until the GPU is dead
the 900 should be possible for you

i modded it using pencil mod and fixed the mod using sticky tape that pencil is not blown away

hmm nice ,.. ok i try one more time to pencil it ...
if 1,5V are possible just with this

now i get about 40°C @ idle...


EDIT:
BANG after i penciled it one more time i could get 940 core speed benchstable everything i wanted
and the temperatures are really cool with 42°C directly after the Bench 3D Mark 06

Now i got 12099 Points

[Vatos_locos]

mine 3850 with 1,65 Vgpu can benche A 1026Mhz Core :p and with 2,25Vdimm @ 2200Mhz Mem i don't know why my mems are so low

http://www.hwbot.org/result.do?resultId=686058

[JamesBong420]

anybody replace the caps on there cards?

my card used to do 1004mhz core and now that i have the chiller on it. it wont even stay constant 972mhz even. i get the dreaded checkerboard artifacts.

[Riska]

Maybe a sort of coldbug on the card?

[Menhir]

hmm nice ,.. ok i try one more time to pencil it ...
if 1,5V are possible just with this

now i get about 40°C @ idle...


EDIT:
BANG after i penciled it one more time i could get 940 core speed benchstable everything i wanted
and the temperatures are really cool with 42°C directly after the Bench 3D Mark 06

Now i got 12099 Points

nice

did u get 940core with 1.5volt?

i cant get more than 905mhz gpu with 1.5volt

my idle temp are 44°C @1.5Volt 905Mhz GPU and AC S1 now @1x92 and 1x120 fans

[JamesBong420]

Maybe a sort of coldbug on the card?

i don't think so.. the card doesn't read colder then 19c. i need to get a few probes.

i just dont know anything about caps. and i heard my checkerboard arties are from my caps blowing ass. and would like someone to confirm this.

[Cha0s]

nice

did u get 940core with 1.5volt?

i cant get more than 905mhz gpu with 1.5volt

my idle temp are 44°C @1.5Volt 905Mhz GPU and AC S1 now @1x92 and 1x120 fans

my multimeter is broken so i cant say what exact volts are on it..
but i cant go higher than 940 or it crashes ... so i think it should be about 1,5V -1,55V ?
now my startup settings are: 940/1040

[Riska]

My Sapphire 3870 can do 1080/1377mhz on water in my shuttle barebone vgpumod set to 1.65v mem stock.

http://service.futuremark.com/compare?3dm06=4614341

[nunchucka]

so far i have reached 945/2000 on this viper 3850 256meg card with a pencil and water block running off a nautilus500 which is cooling my old qx6700 aswell....

13346 score 06:

http://service.futuremark.com/compare?3dm06=4615751

[GenTarkin]

Just Tested the new Pencil Mod and it works great its easier to apply
Here is a image for anyone that is confused about the Pencil mods



The Mod is exactly the same for the 3850 the only difference is the
Resistance measuring point. Its the Right Blue Square and the Screw Above 'Q1252/Q1612/Q1602'
Top left Corner of the image

I am gonna try the old vmod in blue, on top of that resistor R1222... on my 3850...where is the resistance measuring points for the old vmod?

Also, for this to work do I have to have a vbios that is set at appropriate voltage to "unlock" the hard mod..or does this override the specified vgpu voltage in BIOS?

[Rumon]

The measuring point is that resistor itself and i don't think you need a specific bios for it to work. I found that the blue pencil mod is a bit harder to do and I'd recommend using a soft pencil 2H/2B/3B

------------------------------------

My Sapphire 3870 can do 1080/1377mhz on water in my shuttle barebone vgpumod set to 1.65v mem stock.

http://service.futuremark.com/compare?3dm06=4614341

that great i have not really used water cooling but plan on putting together my first WC setup in a couple of months. What water block are you using on your card?

[GenTarkin]

well, whats the technique for second pencil mod? do I have to be careful to how much lead I get on that one too? or...do I just connect the dots with any amount of lead?
how is it harder exactly? It seems like it would be easier to get right amount of lead between 2 ends of a resistor then to try to get the right amount of lead between 2 solder points...no?

[Rumon]

The main reason the old mod is harder is the fact its hard to actually get the lead to stay on top of the resistor.

With the second pencil mod i simply bridged it with lead (much easier to apply and it stays), use DMM to measure resistance and simply grazed the lead with my DMM reader to take some lead off. Until i eventually got the resistance up to what i want.

hope that helps if it makes sense

[GenTarkin]

what should be the target resistance of the newer mod?

[Cha0s]

i penciled the old mod how much i could... and now i get stable 940 with the 3850... so i leave it so..
and i hope the lead wont get away ^^

[GenTarkin]

I did the old mod as well....penciling it was much easier, those solder points on new mod would just not connect for me...

I penciled it to like 1.249 ohms...Im not sure what vgpu that puts me at...

does anyone know of any measure points for voltage really close to the edge of the board on the side, cuz my vid card is very hard to measure since my cpu heatsink is so huge!...leaves me no room to put probes halfway in middle of card...