ATI 3850/3870 Voltmod thread

[Norway]

Hello guy´s

I have made the vgpu mod on both mine HD3870 one Club3d and one Asus and i have flashed in a better bios thats unlocked from the 862mhz lock.

But now i have a new problem. The cards are running with WC and i have 1,4v in 3d mode so they make easy 950mhz on that voltage. But i cant overclock card number 2 only number one in rivatuner and other programs. And if i use CCC i only get to 885mhz on the core and thats even not near what i want. I have pushed made a 3d06 round in 1077mhz on the core at eatch card i singel so i need some kind of mod to any program so i can overclock them in win to 1077mhz.

Any suggestions?

Use this BIOS, it will unlock CCC to numbers you only can imagine
It also set 850/1200 to default

[TheMan89]

THX! I hope CCC will give up now

[TheKarmakazi]

Use this BIOS, it will unlock CCC to numbers you only can imagine
It also set 850/1200 to default

Will this also work on 3850's or is there a similar bios that would?

[Cairnsey]

@ Jimbo Mahoney - Could you point me to the correct resistor for a pencil mod, we have the same cards, actually you might remember me from OcUK forums?

Would it simply be C652?

Cheers

[Norway]

Will this also work on 3850's or is there a similar bios that would?

you can find it here.

LINK

[jimmyz]

Will this also work on 3850's or is there a similar bios that would?

those are included on the disc I sent you and a few others.

[lowtcell]

Use this BIOS, it will unlock CCC to numbers you only can imagine
It also set 850/1200 to default

I just tried your bios on my new Diamond 3870 and it clocks like a beast, but the fan speed is too low. Anyone have a similar bios that has better fan control?

[Norway]

Just use rivatuner and do so it goes on 60% 24/7

I use rivatuner and for me it work prety well

[lowtcell]

Just use rivatuner and do so it goes on 60% 24/7

I use rivatuner and for me it work prety well

This is for Crossfire setup, from what I read, Rivatuner is no good for tweaking dual cards.

[JaD]

I recently got myself a second Powercolor 3870 PCS that has a newer PCB revision (1.1 instead of 1.0) with some minor differences.


(It's KOhms, wrong corrige).

In the 1.0 PCB, i have shaded a resistor placed on the same spot of the red marked one, which had a default value of about 2KOhms.
On this new one its resistance is higher, and the controller chip is a NEXSEM NX2422 instead of a uP6201AQ VLK78W.

Would it be fine to shade the "red" resistor aswell?

[todda7]

Can anyone measure which voltage they get at 50k ohm vGPU? I only have a 50k pot:P

[ante_ante]

Use this BIOS, it will unlock CCC to numbers you only can imagine
It also set 850/1200 to default

Bought " TheMans " cards yesterday, today i recieved it and flashed with that bios u mentioned. Working like a charm, can go up to 1500mhz on core in CCC on both cards now

[Benji Tshi]

Hi everyone,

I got two Asus 3870, but they are based on a modified PCB by Asus.
Did anyone have found the vmos for this kind of card?

Thx a lot

[Vatos_locos]

post some good pic's

[Benji Tshi]

You're right. Nothing to take pics at the moment, but I will post it asap.

I was just expecting that someone can answer me without pics (perhaps this vmod have already been found).

See you

[Vatos_locos]

i don't know if they exist already but some pic's should be useful to figure out the mod from scratch

[Benji Tshi]

As promised :

[-DC-]

omg... i have the same one (two to say wxactly ) and i can do nothing((((

[Benji Tshi]

Noooo!!

I have buy 2 pieces to test the Crossfire...It was looking good but if vmodding is impossible

I'm waiting for another geeks to answer me, and i'm looking for deduce this vmod of the other which already exists.

[Vatos_locos]

Benji Tshi post an other one the front side of the card...

[Benji Tshi]

Sir, yes Sir !

[-DC-]

i think you'd better redo the photo. without cooling system

[Vatos_locos]

i thing that these two are the chips if you can some good pic's of them and tell us what is marked on the

[Benji Tshi]

I did it the best way i can...

[Vatos_locos]

grr i hate asus i googled them and i cant find datasheets for them post an other pic of the card naked...