ATI 4850/4870 voltmod thread

[gurusan]

i wish.. can bench anywhere from 900-940 core/~1090 mem

havent monitored voltages

What's your highest gaming stable clock? And what do you mean you haven't been monitoring voltages?

[G-UNIT91]

G-UNIT91, why You need that?

I'm working on handmade's cooler

[largon]

Well so why its more stable, cooler and allow higher OC at same voltage then average 4870 using 3 phase digital VRM?

Phases aren't created equal.

[DemonEyez]

I haven't got time to mod my Asus, but friend of mine gave me his two Gainward HD4850 512MB Golden Sample




Other pics: http://ceemic.pri.ee/hardware/hd4850gs/

Def Vgpu changed (idle/load) 1,194V/1,214V -> 1,207V/1,221V

Dude, you're my hero. I just got this card few days ago and was searching for some mods. Nice pictures!
Are you plannning to do a voltmod for the ram also?

[ceemic]

DemonEyez, these are my friend cards. He only wanted Vgpu mod. Vmem mod doesn't help alot. Also, it has 0,8ns chips which overclock better

[DemonEyez]

DemonEyez, these are my friend cards. He only wanted Vgpu mod. Vmem mod doesn't help alot. Also, it has 0,8ns chips which overclock better

yeah I know. Did some testing and I can do 1175MHz on the 0.8ns Samsung chips.
If I do 1200 I get instability. So I was just wondering if these Samusng chips like more voltage.
Any idea how much they run on at stock speed?

And just to be 100% sure, this is vGPU mod right? :

[ceemic]

Yes, You can use all these points:

I soldered over the two point marked with blue lines

[NapalmV5]

What's your highest gaming stable clock? And what do you mean you haven't been monitoring voltages?

nope no monitoring.. lol

gaming @ 900/1075 comfortably

[ceemic]

NapalmV5, have You done cap-mod for HD4850 also?

[G-UNIT91]

I'm working on handmade's cooler

please ceemic

[ceemic]

G-UNIT91, these were my friend cards. I don't have them anymore and can't do pics...

[G-UNIT91]

G-UNIT91, these were my friend cards. I don't have them anymore and can't do pics...

ah ok, sorry

[NBF]

largon, tnx again!


Use 100k or 200k VR. I'll do the mod ASAP and report back

Have you tried this mod?

I had litlle time to play, just set the VR to give 10,5K OHM, but it didn't seem to raise VGPU. Haven't double checked it yet, but I wonder if it worked for you.

[ceemic]

NBF, no, I haven't had time yet.

But try to lower resistance more. Sadly I can't be sure if that is 100% the FB pin

[Krautmaster]

hi @ all, I'm new here in this great forum.

Have some questions because I want to mod my Gigabyte HD4850 reference design. Its my first mod . I have a water-cooled system, PA120.3 + Laing Ultra.
Which is the best cooling solution for me, with a reference voltmoded 4850? I don't want to spend additional 100€ for a GPU w nearly the same price. Tought about 50-60€.
Shoud I buy a Swiftech MCW60-R universal Rev. 2 (42€) + little Ram an VRM coolers (where to buy?) - or shoud i buy the Heatkiller Watercool HK GPU-X2 Ati 4850 LT for 59€?



Is the cooling performace of the HK good enough to clock the card towards 850-900 Mhz? Mem + VRM cool too? Don't know if the reference design HD4850 can do this. Especially the VRM, what can i do to hold them on low temps? Will the Swiftech the better solution for me? May i able to use the Siftech on comming GPUs again?
Perhaps somebody have the time to list what i've to buy for ideal cooled OC HD4850.

Thanks a lot - sry for my bad english
Greedz from Germany


Edit:

Bought a Swiftech MCW60-R + 2 Zalman ZM NB47J and 2 Zalman ZM-NB32K witch I will cut into pieces and fix onto the phases and VR

Edit2:

Card is here, goes for 700/1100 without problems in renamed Furmark (~4900 points on standard settings). Fan at 90% für benching. No Mods done so far, standardcooler. Watercooler an resitors will come on friday. =)

[GamerBR]

I'm needing some assistance here,I was trying to discovery an alternative point of soldering for my non reference sapphire card(it does not have that "big" pad like the reference one),so I followed the trace and discovered one resistor that with my multimeter was measuring exactly 0,so what I did was to remove it,make a bridge between the points and solder a wire to it,after that the card doesn't boot anymore,which doesn't seems to make any sense,any idea what might happened?Also I lose the resistor so I can't put it back anymore,can anyone please measure the resistance of R656 so if it's not zero I can solder a trimpot to the points and set the original resistance?It doesn't need to be from the same card,any reference card will almost for sure have exactly the same resistance I'm looking for.
Thinking better,the problem might not be that,I tried to use "conductive" glue on the leg of the chip(it does not conduct very well,about 1000 ohms),after seeing that I would not be able to use it I cleaned as much as I could(apparently there is no glue left),but some of the glue might have flow underneath the chip,can anyone please measure the resistance between these two points to see if that is my problem(the last leg and the one left to it)?Again,it does not need to be from the same card,any reference one should have the same resistance.

[Krautmaster]

my unmoded reference card with standard voltages and only fan mod does 730/1100 , more not tested yet. Furmark gives me about 103 °C without errors, tested crysis for about 2 hours stable with about 95°. MEMIO is always the highest temperature. Idle 75° fan @ 20% load fan @ 95%

[Gangsta73]

@GamerBR : i can measure this resistor, but can u please mark it on the picure, cant find R656 atm.
If possible contact me, via ICQ #46700077 cause i am only here from time to time, and i think your request is urgent?

[GamerBR]

@GamerBR : i can measure this resistor, but can u please mark it on the picure, cant find R656 atm.
If possible contact me, via ICQ #46700077 cause i am only here from time to time, and i think your request is urgent?

I added you on ICQ,but I don't have it installed here anymore,so I entered on ICQ2Go,apparently you are not online now.I suppose you have the same card as mine right?I marked on the picture which resistor it's.Could you also please measure the resistance between the other two points marked?Now I think it's more likely that this is the problem,it doesn't make much sense that removing a resistor with no resistance at all and linking the points with solder could make the card stop working.

Thanks for the help

[ceemic]

Have you tried this mod?

I had litlle time to play, just set the VR to give 10,5K OHM, but it didn't seem to raise VGPU. Haven't double checked it yet, but I wonder if it worked for you.

I just tested it and IT DOES NOT WORK
That's not FB. Also I moded pin #1. No go

[NBF]

I just tested it and IT DOES NOT WORK
That's not FB. Also I moded pin #1. No go

Sad news

I was hopping that I had done something wrong.

Back to starting point, unmoddable card

[ceemic]

NBF, that's pretty bad yeah
But I will do what I promised: I'll solder VR to every pin and start to look which works 2 down, 14 to go

[NBF]

NBF, that's pretty bad yeah
But I will do what I promised: I'll solder VR to every pin and start to look which works 2 down, 14 to go

I hope you find the right one

Seems like you are pretty shure the AP-AG controls VGPU, otherwise we would have extra 24 pins to check on the BD-AF

[ceemic]

NBF, I talked with my friend Jaan (some of here might know him for his exteme Vmoding skills) atm. He gave some hints how to look right place. I'll do some measurements and report back. And it can be the BD-AF IC

EDIT: I tried to figure something and here are my thoughts:

First bet would be "14" marked on my pic. Resistance to GND is ~1002 ohm (~1,0k ohm). If You have time maybe You can confirm it? 20k VR should be safe. There are many good soldering points. Sadly, I don't have time to try it next 2 days...

[ceemic]

IT WORKS


So I used 20k VR and Vgpu rised pretty lot (I used ATi Tray Tools to adjust Vgpu and render 3D):

Before Vmod:
1,044@ATT -> 1,209V/1,322V (2D/3D)
1,158@ATT -> 1,339V/1,328V

After Vmod:
1,044@ATT -> 1,268V/1,386V
1,158@ATT -> 1,405V/1,392V






EDIT: I recommend a switch for 24/7 use, because 20k VR rised Vgpu a little bit too much and it boosts GPU temp! PWM and PCB temp even more!