ATI 3850/3870 Voltmod thread

[os008]

Indeed, i chipped off a resistor, and lost hope of ever getting the card up and running again, and i actually put it with the old computer stuff that i don't use, never thinking of RMAing it, although, i could easily glue that resistor back, and it will never look like it was tampered with.

Then i took out again, and tried that VR thing, and it worked, now, can you guys look into the thread i made, and tell me how much resistance is that resistor i circled yellow.

Thanks.

[Norway]

Approved

[Klimpen]

Nice done Norway. Is far as I can see that is a 3870, right?

I am about to do the exact same thing as you have done and I was wondering if you can take 2 more shots with your camera for us.

One that shows a more close-up of the red cable-end from the CORE mod.
The soldering point in the middle of the card.

And please another close-up of the IC that you soldered the two pink cables to.

What kind of adjustable resistor did you use? Is they both 100Kohm with 15 turns?

Thank you very much!

Klimpen from Sweden!

***EDIT***
How come you connected the pink cable from the CORE pot to the IC? Isn't it supposed to be connected to GROUND?
As Rumon shows in THIS PICTURE.
You are getting med confused. As far as i know you connect a resistor between a specific spot and ground.
But I'm no scientist so please correct me and prove me wrong

[largon]

How come you connected the pink cable from the CORE pot to the IC? Isn't it supposed to be connected to GROUND?

It doesn't matter what spot the VR is grounded, as long as it is on ground plane...

[zanzabar]

for the new pencil mod here
http://img205.imageshack.us/my.php?i...870pmodsl4.png

what if u did both points with a higher ohm than on one of the points only so that it would be easier to shade in

[Vatos_locos]

the Vdimm mod is tha same for HD3850 ? how many kΩ for the pot ?

i made the Vmod first with 50k pot 25 turns and i got ~ 1,4Volts so i used one more in series an got +0.01 Volt @ 100K from stock of 3850 Vga
just like Norway did with the Vcore mod and it works fine with 1,55V i can bench @ 1Ghz Core

[Norway]

Nice done Norway. Is far as I can see that is a 3870, right?

Right

I am about to do the exact same thing as you have done and I was wondering if you can take 2 more shots with your camera for us.

I'll do it littlebit alter

What kind of adjustable resistor did you use? Is they both 100Kohm with 15 turns?

500Kohm 20 turns from elfa.se
type 89P

How come you connected the pink cable from the CORE pot to the IC? Isn't it supposed to be connected to GROUND?

The pin that i use on the IC is the IC's grounding ...


The old solder that was there didn't even melt on 480C so the soldering dosen't look that good but it does its job

core:


IC:

[gurusan]

Has anyone discovered a vDIMM pencil mod for the 3850?

Where at least can I measure the stock vDIMM?

[gurusan]

I just measured these points and they all read 2.10 volts. Is this the vDIMM?

[Vatos_locos]

Has anyone discovered a vDIMM pencil mod for the 3850?

Where at least can I measure the stock vDIMM?

stock Vdimm is 1,9Volts have you tryied to see whits resistor ends on the leg oh the Vdimm ic ?

[Niccolò]

stock Vdimm is 1,9Volts have you tryied to see whits resistor ends on the leg oh the Vdimm ic ?

Mine is 2v vdimm stock. I brougth it to 2.2v but could reach only 1050Mhz on mem. I was hoping for more. Those who made this mod had the same experience?

[Vatos_locos]

Niccolò I haven't done the Vgpu yet but when i was searching for an unlocked Bios for my 3850 i saw this

on stock bios my mem's could go up to 2400Mhz DDR
with the Bios i am using now i can go only up to 1000Mhz DDR

try with 2,3 Volts if you can go further

[Niccolò]

2400 with ddr3 seems a lot. It looks like impossible.

If you're looking for an unlocked bios for the 512mb version i can give you mine that doesn't have the 864 block.

Look

[Vatos_locos]

nope i could go up to 2394Mhz with the locked Bios
i have Bios now and i have the 256Mb Card so i could go with more Mhz on the ram's

[Niccolò]

You could reach this with stock voltage? If yes, that's awesome. I tryed but of course it crashed.

[Vatos_locos]

yheap i could reach those speeds with stock voltage but with the original Bios Only when i changed with one unlocked the core speed could go farther but the mem's could go only up to 1050Mhz ( 2100 DDR ) but you should try to get more Mhz for the core and then from the mem

with the unlocked Bios the card Vmoded ( only the core not the mems ) i can go up to this i need a bios tuner to flash the card with the same bios but higher clock speed couse riva tuner the core speed selection ends at 1005Mhz ( 999Mhz on gpu z )

[FINRamona]

I make my card pencil mod and now vgpu is 1.489V, i just run 3dmark06 core 985Mhz and mem 1278Mhz.

Card cooled HR-03/R600+ Adda 120mm. idle temp 40*c AND LOAD 6h atitool torture 53*C, core 930/mem 1280

http://service.futuremark.com/compare?3dm06=4485045

[Norway]

2400 with ddr3 seems a lot. It looks like impossible.

I can do 2430Mhz on mem om my 8800GTX with just 2,24v and that is GDDR3 ....

[Sage]

Norway what volts and speeds did u get after the mem mod?

[Norway]

Havent have time to the speed yet but i can go very high with the volt, but haven't gone any higher then 1.95v and that was very hot, to hot on the stock copper cooler becuase it was cooler passive ....

Testet 1400Mhz with ATItool's 3Dcube and it was stabile there, my aim is 1500Mhz 24/7 when i get my fullcover waterblock (Aquacomputer), I guess 1.95v orginal cooler is possible with some activ cooling.

PS... didn't try to go any higher than 1400Mhz .....

[gigolo]

I try pencil mod now I can run core 850 Mhz and mem 1143 Mhz on Stock Heatsink. but I can't go pass 860 Mhz
http://www.vmodtech.com/modules.php?...wtopic&t=22803

[Vatos_locos]

I try pencil mod now I can run core 850 Mhz and mem 1143 Mhz on Stock Heatsink. but I can't go pass 860 Mhz
*image*

you need the unlocked bios to pass 860Mhz on core and you could run your rams @ lower timings all 5's i thing (?) can the run there ?

[gigolo]

you need the unlocked bios to pass 860Mhz on core and you could run your rams @ lower timings all 5's i thing (?) can the run there ?

If you have unlocked bios, can you upload the bios. Thank you very much!

[Vatos_locos]

sure why not it's for 3850's 256Mb only be sure that you have 3850 with 256Mb Vram

use atiwinflash or atiflash to flash your card's bios

this one i'am using with one sapphire 3850 256Mb and i can go up to 1Ghz riva tuner cand go farther the card can go farther tho but we need a bios tuner with 38x0's support

[Norway]

Rivatuner can go far higher you just need to do some magic in the Power User thumbnail :P

You can also set ATItool to go higher .....