ATI 4850/4870 voltmod thread

[gurusan]

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.

here are some pics.

[ceemic]

ptys, basically Yes.

[ptys]

ptys, basically Yes.

mod work, thx master 1.35v 825mhz full stable, em used 50k VR

[DuncanOc]

guys,any possible pencil mod?

[ceemic]

DuncanOc, yes, but we need a good macro picture from that IC, so that we can see where FB pin heads to. Use Your DMM and search all points where FB goes. When there's for example a SMD resistor or cap what has GND on other end, You can use that for pencil moding.

[ziggo0]

Alrighty, I got my 200k pots in the mail, now that i hook the 2x pcie connectors up and check pin 19 with the multi meter set properly, I'm only measuring 9.4 ~ 9.5kOhms...is something wrong?

[ziggo0]

Can somebody please measure the resistance for those 3 circled items? When soldering on a wire...it popped off and took a resistor with it (I corrected this one) and doing that...removed the main circled one...so I have no idea what it's resistance should be. Please help

[8800's@over]

My First V-Mod : D


























870/3800MHz

[ceemic]

8800's@over, this 1-turn trim-pot' is too risky

[8800's@over]

8800's@over, this 1-turn trim-pot' is too risky

This is more exciting


Man, it has protection against Overvolting?

If yes, what vCore where he qualifies this protection?

[ceemic]

OVP is a little different on every card, but should be on ~1,7V range...

[8800's@over]

[8800's@over]

I'm having problems and I come here to ask for help you,

My card is very instabil , I do not have a multimeter to see which is the exact voltage, temperatures are relatively good, I'm with the XOC BIOS, I can now reach up to 880MHz in AtiTool without artifact, black screen when I have more road OCCT GPU and VPU recovery times in the games and many artifacts.

What should I do?

Remembering that I have very little experience in v-mods.


May be guilty of my Trimpot?

The Weld may be poorly enforced?

[winbond]

8800's@over, if you don't have a good airflow over the entire card, it will overheat...

i have a watercooled 4850 running 760/1140 on stock voltages and it overheats and shuts down if there is no fan blowing air over it, even though the core is in the low 40s


...btw, i haven't looked through the entire thread yet, but is there a hard volt mod? i'm looking to run about 1.36-1.4v

[Gir92]

I'm having problems and I come here to ask for help you,

My card is very instabil , I do not have a multimeter to see which is the exact voltage, temperatures are relatively good, I'm with the XOC BIOS, I can now reach up to 880MHz in AtiTool without artifact, black screen when I have more road OCCT GPU and VPU recovery times in the games and many artifacts.

What should I do?

Remembering that I have very little experience in v-mods.


May be guilty of my Trimpot?

The Weld may be poorly enforced?

I don't mean to sound harsh, but why would you even think about volt modding without a multimeter?

[winbond]

can someone confirm if this is correct, i took this from 2 different posts and just want to know if it can work on my card:
i have asus 4850 top with 3 phase power


now what i want to do, instead of a pencil mod is to solder a resistor there, to the points in the green circle...
i want to know what the value of the resistor should be to get about 1.4v at load...

i found this values in the other post but not sure if those relate to what i'm trying to do here

10 ohm fixed ~ 1.566v
15 ohm fixed ~ 1.465v
22 ohm fixed ~ 1.400v
27 ohm fixed ~ 1.375v
33 ohm fixed ~ 1.355v

edit, well i tried to use a 22ohm resistor, but it only added more resistance to the circuit instead of decreasing it,
obviously i lack basic understanding of electronics,

how come when i add a resistor the resistance increases, but i can connect a 100k pot and it doesn't increase the resistance by 100k,
pot is just a variable resistor, this doesn't make sense to me

[8800's@over]

Lower the voltage is lower than in stock, it seems impossible now she is more stable 830/4200MHz, before barely get 820Mhz.

Idle (500/4200) 42° Load (GTA IV - 830/4200) 53°. Stock Cooler

[8800's@over]

Will my trimpot is not holding?

[miahallen]

With the OVP/OCP...what happens if your trim pot is truned the wrong way when you power on your card for the first time? I think this is what I did to one of my 4870s and now I get no output. I removed the mod, and ran it as a secondary to attempt a bios flash...but the ATIFlash tool doesn't even detect the second card...is it dead for good?

[winbond]

With the OVP/OCP...what happens if your trim pot is truned the wrong way when you power on your card for the first time? I think this is what I did to one of my 4870s and now I get no output. I removed the mod, and ran it as a secondary to attempt a bios flash...but the ATIFlash tool doesn't even detect the second card...is it dead for good?

i think it's fried, man

[miahallen]

Thanks winbond (I think you're right). I've already contacted PowerColor to see if they'll let me RMA...just trying to exhaust all options....anyone else?

[ceemic]

RMA'ing something that You consciously killed?
Now that seems unethical, IMO...

[DemonEyez]

8800's@over, if you don't have a good airflow over the entire card, it will overheat...

i have a watercooled 4850 running 760/1140 on stock voltages and it overheats and shuts down if there is no fan blowing air over it, even though the core is in the low 40s

Same here, I have two Palit Dual Sonic HD4870 which shut down rather quick when there's not enough cold air blowing over the cards, eventhough the GPU temps are not so high.
They don't shut down though, but produce heavy artifacting, it's mainly the GDDR5 which start to artifact.

I'm thinking of skipping on the voltmods for these cards. I fubared my last Gainward HD4850 when i was removing the volmtod on the GPU. I gave the wire just a little too much heat en when i pulled it of the whole solderpad came with it. Tried to fixed it, but in doing so I f*cked up even more. ( so if anyone is interrested in a dead Gainward 4850 GS for spare components, just give me a PM)

Right now, I can do 860/1000 with stock voltage of 1.263v on the first card ( still testing the second)

I was wondering, does a HD4870 benefit more from a GPU overclock or a ram overclock? I know that with the HD4850's it is the other way around beacuse those card are rather bottlenecked by the GDDR3

Oh and btw, doing a RMA after one has fubared the card by bad modding is so lame.

[miahallen]

RMA'ing something that You consciously killed?
Now that seems unethical, IMO...

Unethical?...I'm not forcing them to do anything...it's totally up to their discretion whether or not they'll process the RMA. I don't expect them to go through with it, and if they don't I wouldn't be upset...but if they do, they'll have earned my respect and possibly future sales.

I worked in the retail channel for many years, and the RMA process was not always for products that were covered under the written warranty...in fact, a majority of the time, they wouldn't have been covered...but the manufactures like to take care of their customers...sometimes even in extreme situations.

Besides...if their OVP was working correctly, this wouldn't have happened j/k

[8800's@over]

Above 830MHz I do not have stability, regardless of voltage, OverClock of bad card?

Above it in FURMARK or games Halting and BSOD

Bad BIOS ? (OCX 795/1100 1.276v