Hd 3850 Pencil Vmem mod?

[fng77]

Hello!

I´m new in this forum. I´ve read about everyones V-core mods and i´m impressed. Both about you guys who sort thing out and also everyone whos breaking new records. I have a 3850 myself and I would very much like to se a pencilmod for the memory. Does anyone know if such exists?

[Riska]

http://frip.dk/riska/3870gddrcontrolfinalql8.jpg

Try shading this resistor marked in green and blue with a pencil and remember to meassure the vmem all the time so you not get it to high

[HousERaT]

would this be the same for the 3870?

[Riska]

Yes i would say so

[Riska]

"""@eva2000 try to measure point 1 and ground and see if it has 0 resistance then measure point 2 and 3 and see if the have 0 resistance iφ so the it should be the smd resistor between point 1--2 but you should wait for some one to tell you where the pencil point is for sure or try to lower this resistor 10-20 Ωhm and see if it raise your Vmem"""
it is from the vmod threadon the last page

http://www.xtremesystems.org/forums/...166623&page=13

[akin]

@ Riska :

how about the resistor on the lower side of the blue marked ?
is this resistors can be shade too, to rise up the memory voltage ?

i try to measure this resistor, the right side leg is connect to the marked IC's leg and the other side is connect to ground..

[Riska]

They are all 3 connected on the side of the chip so i will think so

[fng77]

Thanks Riska, youre the man. I´ll try that tonight. Will let you know about my progress =).

[gurusan]

i have a powercolor 3850 512mb and would like to figure out a pencil Vmem mod...but my PCB is different than the one above.

I shaded the marked resistor a bit with a pencil but it brought my Vmem DOWN!!! From 2.1 to 1.85v

That aint cool!

[Riska]

You should try to shade this one marked in green..

[fng77]

I shaded that resistor and my voltige drooped too. My Sapphire 256 Mb had about 1,92-1,93 at the measurepoint orginal. One loose shade gave around 1,7 V. I even managed to get 0,6 V wich resulted in totalt shutdown.

[Riska]

Ok then i am lost and cant help u

[fng77]

No worries. Thanks for youre help anyway. If you figure somthing else out please let me know.

[Cha0s]

do you now what resistance R711 has?
i want to change the resistance with a second parallel resistor but i need to now how hight this one is

[S_A_V]

pencil vmem - R710:

[Cha0s]

after i penciled i get artifacts much faster than before... my multimeter is broken so i just can say : penciling R711 like in the first picture above makes mine card react on memoryspeedincrease worse than before,..
strange?

i got a HIS HD 3850 with 256MB

[Rumon]

I tried out the pencil mod here i pic of what i found out



Shaded R710
4.07KOhms = 1.95v
3.94KOhms = 2.00v

I tried both 1.95/2v and it seems to perform worse in ATI Tool 0.27 artifact test then stock 1.9v
i don't know if its the Mod or just inadequate cooling.

Ah well I'm happy with with i got currently just though I'd give it a shot.

[Cha0s]

I tried out the pencil mod here i pic of what i found out



Shaded R710
4.07KOhms = 1.95v
3.94KOhms = 2.00v

I tried both 1.95/2v and it seems to perform worse in ATI Tool 0.27 artifact test then stock 1.9v
i don't know if its the Mod or just inadequate cooling.

Ah well I'm happy with with i got currently just though I'd give it a shot.

ok : pencil R710 will raise volts? damn and i penciled r711 xD and wondered about pixelfailures -.-
hmm and what cooling you got on your rams?
and how high could u now do your rams?

[Rumon]

My current setup is listed in my Sig (mem@1251) i didn't use the including ram sink for the Accelero as they have a tendency to fall off so its got the stock ram sink.

-----
@ChaOs
I just realized i got the AC S1 its got 4 heat pipes never got around to updating sig ^^

[Cha0s]

My current setup is listed in my Sig (mem@1251) i didn't use the including ram sink for the Accelero as they have a tendency to fall off so its got the stock ram sink.

hm i got the 3850 and a accelero S1 +2' 92mm cooler
thats enought for now...
------------
EDIT
Now mem is 1040..works... but higher wont work...
ONE MORE:
1062 now...

[fng77]

I tried out the pencil mod here i pic of what i found out



Shaded R710
4.07KOhms = 1.95v
3.94KOhms = 2.00v

I tried both 1.95/2v and it seems to perform worse in ATI Tool 0.27 artifact test then stock 1.9v
i don't know if its the Mod or just inadequate cooling.

Ah well I'm happy with with i got currently just though I'd give it a shot.

Mod confirmed on my Sapphire 3850.


I almost fried my memory with this mod. Stupid as I can be I gave this resistor a good shdade with my computer tured on. After a while i found my multimeter and the Mem voltige was 3,5 Volts!!

I tured of my computer in a hurry and used the eraser. With a soft shade I landed on about 2,14 Volts. This didnt do any difference in rivatuner, got artifacts as usule around 1050 mhz. Gonna try 2,25 V tomorrow.

[fng77]

I tried out the pencil mod here i pic of what i found out



Shaded R710
4.07KOhms = 1.95v
3.94KOhms = 2.00v

I tried both 1.95/2v and it seems to perform worse in ATI Tool 0.27 artifact test then stock 1.9v
i don't know if its the Mod or just inadequate cooling.

Ah well I'm happy with with i got currently just though I'd give it a shot.

By the way, Thanks for sharing your findings Rumon!

[fng77]

Damm. If I rasie the V to 2,25 I get artifacts at stock too. Wonder why?

[Riska]

I have the same problem on my 3870 gfx nomatter if it is stock or up to 2.22v it will not go any higher than 1377mhz i think that there is missing something to the vmem mod like a vdq mod or something!
Can somebody please confirm that they have got any higher mhz on the mem with vmem mod?

[fng77]

Yes, that would be good. Im with Riska. Anybody is welcome to confirm higher mhz with this v-mem mod.