ATI 4850/4870 voltmod thread

[petrakov]

hi
how voltmod my powercolor hd4870 512mb,ddr5 PCS+ rev1.0 ?
gpu voltcontroler NCP5388

where need put resistor to voltmod GPU ?

resistor=? ohm,kilo ohm

[ceemic]

petrakov, use search in this thread. Here are many different cards with that IC.
Pin #19 is FB. Look where it goes to find better soldering point. Remove card from PC and measure resistance between FB and GND. Multiply that value with 20x and You'll know what VR to use.

[petrakov]

powercolor HD4870 512mb PCS+ rev. 1.0
voltcontroler NCP5388 pin 19 ist VFB

see thes pic
how to connect VR?
pic 1 -GND to VR to point A?
pic2 -GND to VR to PIN19 ?

Where do I measure the voltage?

[petrakov]

please help
how to put the VR and where to voltage example of GPU?

[ceemic]

petrakov, You can use any spot that is directly connected to FB pin. Use some bigger for easy soldering. The "A" on pic1 seems the best.

Vgpu measuring points:

[petrakov]

thanks broo !!!!
I can put VR directly on PIN19 thes ist not problem for me,but will be correctly?
Which is better
GND-VR-DIRECT PIN19?
GND-VR- dot A


stok Vgpu=1.295v Vmem=1.570v in 3D
these days will put VR and will share results
voltcotroler memory ist uP6101BU8 VFB = PIN6
Is it possible Pencil mod?
see PDF pic,thes ist principled schematic uP6101BU8

(sorry for my bad anglish)

[ceemic]

petrakov, if You shade that resistor with pencil, Vmem will drop, not rise

This is right:


But I still suggest VR, not pencil. Mem chips are very sensitive about too intensive voltage rise.

[petrakov]

blue resistor is 1400 ohm

VR=?

GND to VR to direct PIN6?

[ceemic]

What is resistance between GND and FB? 1,4k ohm?

[petrakov]

ncp53388
R1 - direct GND from 2x6pin to direct pin 19 = 15k
R2 - direct pin 14 AGND to direct pin 19 = 31k

What is right?

R 1 x 20 =VR?



R 2 x 20 =VR?

uP6101BU8
direc pin 3 (GND) to direct pin 6 =1.5k x ? = VR

[ceemic]

You need to measure more. There can't be any difference between GND and AGND.

For Vmem mod I suggest 50k ohm VR.

[petrakov]

Tomorrow I will make new measurements.but I think that there is no error.is measured 3 times
tanks agen broo!!!

[petrakov]

direct GND from 2x6pin to direct pin 19 = 15k thes ist correctly resistance

15k x 20 = 300K VR?(470k standart)

i make vmod memory wet VR 47K,mod ist work,now U=1.710v (stok=1.570v)memory clock now 4500mhz (not work in 4600 - artefacts)

what is the maximum voltage DDR5? (Vmem=?v max not damage memory)

[ceemic]

I haven't seen any 47k or 470k multi-turn VR's. They must be ~15-20 turn, like these: http://ceemic.pri.ee/hardware/_trimmers.jpg
Usually they are 1k, 5k, 10k, 20k, 50k, 100k, 200k, 250k, 500k etc.
500k ohm is very safe to use.

[petrakov]

thes ist VR 470k (0-470k)(474=47 wet 0000)
im put thes VR in GPU vmod today

vmod memory ist make now and works god,but i dont no Umax memory (ddr5)?

[ceemic]

This is one-turn potentiometer. I wouldn't use it, because a little adjustment equals too big voltage change. Too unstable and dangerous.

[petrakov]

vmod ist ready

CEEMIC,

SPECIAL THANKS,BROO!!!
stok
Vgpu=1.295v
Vmem=1.570v
stok 770/3600 max overklock wet thes U 830/4300

now wet vmod
Vgpu=1.395v (1.410-video card ist not work )
Vmem=1.710v
overclock
880/4500 - 4h play games-no artefact,no problems (but run benchmarking wet Heaven Benchmark v2.0 gpu max 870 ?!?, 880 not work-artefact)

[ceemic]

Nice to see they work
But change these VRs to proper ones

[petrakov]

i make today and thes for cooling
http://www.dprg.org/tutorials/2005-11a/index.html

memory ist wery hot 80-85C,but thes fan cooling back site card and memory temp ist 76-78C

[gbglassen]

Check out this crazy xfx 4850 Core is avarage but the memory is insane. The card is a real pain to overclock but very rewarding.
100kohm vr for both core and mem mod.

vcore:


vmem:



800/1370

[@lex]

I haven't seen any 47k or 470k multi-turn VR's.

I have. Soviet. СП5-3 is the marking. I have 47k, but I'm pretty sure I saw 470k as well.
I guess I could send you a few of those, if you'd like

[ceemic]

@lex, have they really 40 turns? That's pretty nice.

[@lex]

ceemic, I beleive so. Never tried to count, though.

[petrakov]

hi agen frends
my voltmod work wery good but now im need overclocked more GPU
but Ugpu max=1.400V (1.410V gpu automatic off,no video signal)
how to turn off this volt protection?

powercolor HD4870 PCS+ 512mb now overclock - 860/4800,1.385v/1.675v
GPU max temp ist load 60C
MEM max temp 75C
room temp 25-30C

[mAlkAv!An]

1.41V seems to be very early for OCP.
Is that card using the uP6201 to control vGPu?