ATI 4850/4870 voltmod thread

[...mat...]

thanks anyhow.

does someone else know something about the vmem mod on the sapphire dual slot?

[lexey]

Hey, can anyone please help me out and tell me the value of the circled component, which is what I beleive is a capacitor? I was taking off my RAMsinks and while cleaning accidentally pulled it off and lost it.

HIS Hightech HD 4850, the actual card is green in colour but the layout is the same. It is under C635 the second component up from the large capacitor.

Thanks alot!
Alexey

[Vatos_locos]

^ #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

do you mean those two ? and do we know witch one is the Mvddc and witch is the Mvddq ?
i have one of those and i'am going to mod the Vgpu but i want the Mvddc and the Mvddq as someone said MVDDQ can provide more oc headroom

[Vatos_locos]

Since uPI Semi so inconveniently pulled the data sheet and detailed specs for the uP6206 from their site, I was forced to make an educated guess at the location of the FB pin. AFAIK, I'm the only one who has tried this mod but the card has been running at 1.35v for a few days now without issues.

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!

ΟΚ 10κ Vr is not working on the sapphire it dose not adjust the voltage at all

and yes it is soldered correct on the card it gave the card a small bump on the voltage from 1.32V it went 1.36 but thats all not more

how many Ωhms do you measure from the soldering spot to the ground ? are you sure it 10k your vr ? as i measure we need a ~500k vr not a 10k

EDIT

500k Vr did the job fine :p

[syl]

ΟΚ 10κ Vr is not working on the sapphire it dose not adjust the voltage at all

and yes it is soldered correct on the card it gave the card a small bump on the voltage from 1.32V it went 1.36 but thats all not more

how many Ωhms do you measure from the soldering spot to the ground ? are you sure it 10k your vr ? as i measure we need a ~500k vr not a 10k

EDIT

500k Vr did the job fine :p

YIKES! That was suppose to be 100K not 10K. I've changed the caption for the correct value. Thanks for actually questioning it

Your 500K may actually work better if you ever need to get back to stock volts. I chose 100K because it gives me finer control with my shaky hands

[Vatos_locos]

no prob mate but i still cant understand something :p even with the 500k vr my card cant raise the voltages the 500k vr raises it about 0.5 and then it stops i might have done the mod wrong i wll check it out again

[Vatos_locos]

pff done it

[initialised]

Any chance one of you could clock match the 4890 (850/900) and do a couple of benchmarks vs stock 4870?

[syl]

pff done it

Great job finding the pin-out diagram Looks like my original "shot in the dark" mod was a bit off the mark...it's working much better now

I've updated my orignal post with your new info and all due credit

BTW, what clocks are you running with 1.4v? I can only get up to 880mhz Furmark stable.

[syl]

Any chance one of you could clock match the 4890 (850/900) and do a couple of benchmarks vs stock 4870?

3DMark06:

[kemo]

Any chance one of you could clock match the 4890 (850/900) and do a couple of benchmarks vs stock 4870?

It is 850/975

[Vatos_locos]

Great job finding the pin-out diagram Looks like my original "shot in the dark" mod was a bit off the mark...it's working much better now

I've updated my orignal post with your new info and all due credit

BTW, what clocks are you running with 1.4v? I can only get up to 880mhz Furmark stable.

thanks m8

same shi(f)t here i can get 880Mhz with 1.5Vgpu and then i get full of artifacts
my card seems that is not a good overclocker at all
are you using a different bios or the original one ?

[kipps]

Hello!
I'm buying Radeon 4830 next week. I know that every 4830 has the same PCB as 4850. I'm wondering whitch of the cheapest referent cards are the best to do pencil mod (if there's any...): Gainward, Sapphire or maybe Powercolor??? I'd prefer Gainward because of its warranty in my country. My primary object is that I could be able to do pencil mod of that specific card.

Gainward would probably look like this one:


Sapphire:


Powercolor:


I'll change stock cooler with Accelero s1 plus 120 mm fans.
So what are your opinions?
Thanks in advance

[initialised]

Thanks, looks like 850MHz does not give a 20% gain over the 4870

[syl]

thanks m8

same shi(f)t here i can get 880Mhz with 1.5Vgpu and then i get full of artifacts
my card seems that is not a good overclocker at all
are you using a different bios or the original one ?

Now up to 910Mhz Furmark and 930Mhz 3DM06 stable with 1.5V...Mosfets get really toasty running FM though.

I'm using the original bios but it's been modded for higher Overdrive limits.

[Vatos_locos]

pff so it's my bad luck :p
with 1.5 i cant pass 880Mhz and i think the mosfets are getting so hot that the card return artifacts

can you post a picture on how you cool the card plz ?

[syl]

pff so it's my bad luck :p
with 1.5 i cant pass 880Mhz and i think the mosfets are getting so hot that the card return artifacts

can you post a picture on how you cool the card plz ?

It's just a MCW-55 GPU block and a 92mm fan blowing down on the card:

[Vatos_locos]

damn same thing here but the card wont clock good

[SebfromSaxony]

Hello,
can anyone please help me with the OCP and OVP Mod for my Powercolor 4870 pcs+ rev2.
The card have a NCP5388 Voltage Regulator. http://www.onsemi.com/pub_link/Collateral/NCP5388-D.PDF
Vmod is 200K Trimmer from Pin19 to VR.

I flasht the card to 950Mhz Core and take 1420mV for a short Test with LN2. It´s work wonderful since the firts moment. But when i turned up to 1460mV the System crashed under load and the output Voltage goes down to ca. 200mV.

in the Data sheet Page 25 and 33

OVP
The overvoltage protection threshold is not adjustable.
OVP protection is enabled as soon as soft−start begins and
is disabled when the part is disabled...

But if the OVP is not adjustable and works only at soft−start, the reason can be by OCP?
The OCP works via a resistor divider between Pin12 and Pin13. Page 7 and Page 25
Can i pencil the marked resistor to disable the OCP?

Thanks.
Seb


Ps: sorry, its not the best english

[lycanwrath]

That's vMEM. For some reason, which is now beoynd me, I assumed you were talking about vMEM pencil mod specifically...
Anyways, to even tell if vGPU pencil mod is possible I'd need a macro photo of the large'ish black rectangular chip labeled "L6713A" and it's immediate surroundings (area-of-interest greyed out in attached pic with the measuring points).

Attachment 92388

Hello, I finally managed to take a nice close up pic:-


Can you help me in volt modding my vGPU now?

[largon]

lycanwrath,
You have been PM'ed.

[Tommie_lj]

does this mod apply to the 4830 aswell?? its the same board as the reference 4850 board, so maybe its the same mod ?? Please answer

[largon]

If the board is physically the same then it works, yes.

[@lex]

Hello!
I've got now my second 4850, and first was killed by Vmod, I guess. Though I only overclocked and overvoltaged it for playing Crysis, and it was under Accelero S1, after two months of using I've got unrecoverable artifacts on screen, which, I guess, was because of memory, though I didn't make mem Vmod. Guys from seller's support replaced the card (shame on me), I've been using it for more than 4 months by now.
I want to install S1 again on new card, cause it's hot. My question is what to pay attention so the card can function properly? If I'll kill it again they won't replace it, I think.
It's ASUS 4850/512M/A - nono-ref with glaciator fansink, 3-phase power supply. Those humorists from ASUS left it with no MOSFET and memory cooling(mem is completely the same as on reference)! If I install S1, can I overcklock it on stock volts without heatsink on MOSFET? What other risks exist?
Thanks for your work, guys, and for helping noobs like me

[rastaseb]

where can i find the "bios mod method" for the overdrive (700/1200) in the CCC ? I want to push away the limits, but can't find the post here!!! Thx

edit : all is ok now!!!!