ATI 4850/4870 voltmod thread

[its me mario]

Finally I was able to get an account with this webpage. Anyway I have a HIS IceQ4 4850 1gb version and I want to know where do I do the pencil mods for that card?! I read every single page on this forum and I only saw it being mentioned that someone had found out a way to do the vmod for my card. The person even put up the results of benchmarks but did not include any pictures of his/her card... Please help me!

[dragubogdan]

The pic has allready posted: http://i40.tinypic.com/2ryq43m.jpg
You can use one of the two points which are connected to pin17. Measure default resistance between FB and GND. Then multiply the number with 20 and that is the VR You can use.

Thank you Ceemic.Only one more thing is necessary:measure point vgpu.
If i get that i will start do work and came with results.

[ceemic]

dragubogdan, http://ceemic.pri.ee/hardware/hd4850..._mod01_mon.jpg

[syl]

Got some new non-reference Sapphire 4870s...would like to know if voltmodding or pencil modding is possible? I think the controller says up6206ak on it.

For the uninitiated, make sure to first set your VR to its highest resistance before adjusting it down to the desired level while monitoring the voltage. You do not want to start with the VR set to zero ohms.

Disclaimer: Using this mod will void your video card warranty and you alone shall be liable for any resulting damages. PERFORM THIS MOD AT YOUR OWN RISK AND DON'T TRY THIS IF YOU CAN'T AFFORD TO LOSE THE CARD!



EDIT: Confirmed working mod with updated info provided by Vatos Locos

[NapalmV5]

awesome ^ syl thanks for the vcore mod

mines already 1.36vcore @ default

ill give it a shot in a minute.. but gotta find a way to increase gpu clock @ ccc

how about a vmem mod?

does up6206ak also regulate vmem?

[benko]

hello guys, i have softmoded gpu and now i want to pencil mode gpu, i measured with DMM



here is pic, every time i pencil it voltge ram doesnet change

also i have maeasured MVDDC and MVDDQ different(1.66v and 1.55v) but are they need to be the same?

[NapalmV5]

pencil or 5K vrs @ blue marked caps

id recommend 3.3K fixed resistors @ each

[benko]

so i need to pencil mode yors blue marked and not that what i marked on pic for pencil mode??

[NapalmV5]

yes

http://www.techpowerup.com/articles/...voltmods/153/3

if vr/resistor works so shall pencil

just be careful.. pencil kills mem before anything else

[dragubogdan]

Thank you Ceemic.Only one more thing is necessary:measure point vgpu.
If i get that i will start do work and came with results.

CEEMIC, the circuit between FB and COMP is closed with no connection to GND
Whatever the default resistance between FB and GND is 7.24Kohm mean i must use 145Kohm VR.
Here the circuit.

[ceemic]

dragubogdan, FB is definitely connected to GND through some resistors.
100k VR works fine.

[syl]

awesome ^ syl thanks for the vcore mod

mines already 1.36vcore @ default

ill give it a shot in a minute.. but gotta find a way to increase gpu clock @ ccc

how about a vmem mod?

does up6206ak also regulate vmem?

You're welcome! Have you try using TechPowerup's Radeon Bios Editor to raise the CCC's OverDrive limits? I've modified mine to allow GPU clocks up to 990MHz.

Vmem is usually controlled by a separate and less complex voltage regulator IC...I'll see if I can dig up some info when time allows.

[NapalmV5]

thanks whenever you got time

i tried "change to these values" as soon as i got the card but no worky

what i mean by no worky.. after flash when driver loads @ os bootup the screen goes blank and artifacts badly shortly afterwards.. i didnt touch clocks/anything.. "change to these values" only change

my reference 4870 1gb sapphire did the same until i flashed it to the powercolor bios

btw i tried your vcore mod on my toxic 1gb and works great just need vmem mod

i have new lower esr caps coming later in the week.. see how that goes

as for the vmem mod i didnt see any convincing vmem chip lol so ill take a closer look

[benko]

yes

http://www.techpowerup.com/articles/...voltmods/153/3

if vr/resistor works so shall pencil

just be careful.. pencil kills mem before anything else

i have tried pencil moding that but when i measured vddc and vddq they were still same??

what pencil you suggest to use??

[NapalmV5]

^ #2

You're welcome! Have you try using TechPowerup's Radeon Bios Editor to raise the CCC's OverDrive limits? I've modified mine to allow GPU clocks up to 990MHz.

Vmem is usually controlled by a separate and less complex voltage regulator IC...I'll see if I can dig up some info when time allows.

yeh those 2 ^ chips by the mem chips are both up6109 mvddc/mvddq


edit: found it: up6109 pdf

http://www.upi-semi.com/ProductFiles..._DataSheet.pdf

[syl]

^ #2

yeh those 2 ^ chips by the mem chips are both up6109 mvddc/mvddq


edit: found it: up6109 pdf

http://www.upi-semi.com/ProductFiles..._DataSheet.pdf

Thanks Napalm Should be a simple matter of tracing out pin 6 for the mod.

[NapalmV5]

connected both mvddc/mvddq (pin 3 to pin 6) with 22k resistor and now ~1.88vmem up .3 from 1.58

havent tried any other resistance so id say its safe to say a 100k vr to start with

it be nice to have solder points on the back of the card though

[gurusan]

Thanks for all the info syl

[dragubogdan]

dragubogdan, FB is definitely connected to GND through some resistors.
100k VR works fine.

ceeemic , is not working;i solder to the first resistor from FB a VR 100K to GND.
card not even start and i set the VR to 100k before connect.

[ceemic]

dragubogdan, can You show a picture from Your mod?

[dragubogdan]

dragubogdan, can You show a picture from Your mod?

The first pic is from Duncanoc , i just put my card in case

and this is vr but no wire , i just remouve it

i hope is clear , if not tell me and do more pics

[ceemic]

Which pins from VR You used?
Did You check that this point was directly connected to FB pin?

[dragubogdan]

first pin (our look) is unused ,midle pin is conected to GND and last pin i used to go to FB
yes i checked with DMM and have 00.4 ohm on scale 200ohm between FB pin and that resistance
I dont understand what go wrong
a ,VR was turned to maximum(99k)

[ceemic]

I would have used that first pin and middle one, so resistance drops (=Vgpu increases) when turned clockwise.
Pretty strange tho...

[dragubogdan]

Another Pic