ATI 4850/4870 voltmod thread

[ceemic]

Yes I understand, how You soldered it.
So You turned it to the end in clockwise?

[dragubogdan]

When i touched the wire coming from FB to VR actually have 99k between FB and GND and must nothing happened(only when start turns VR) , but the card is shut down like a protection thing

[dragubogdan]

yes i turned it to the end in clockwise.

[its me mario]

No one wanna help me out with the HIS Iceq4 4850 1gb?

[dragubogdan]

any idea ceemic?

[ceemic]

dragubogdan, I don't know; it's pretty strange...
Try bigger VR?

[ceemic]

its me mario, please post macro-pictures from PMW area and IC.

[its me mario]

Thanks for helping me out, really appreciate it!

So I took these pics with a 8 year old camera thats worth about 3 bucks now. It took 46 tries to get a couple decent pics

Anyway here ya go!

http://s680.photobucket.com/albums/vv166/IR0BI/


I think the last pic is the best btw.

[Mean Machine]

I've been through the last 10-15 pages and have been googling my ass off, anybody got a vmod for the Sapphire HD4850 dual slot thingie? I need it badly, and fast, if there is one already, if there isn't I'll cancel my order.

EDIT: Or am I right when I think this is the 4850 mod: http://www.xtremesystems.org/forums/...postcount=1006 ? It could be the 4870 as well, I don't have any Sapphire cards in front of me right now, so I can't tell really. Appreciate some help on this.

[ceemic]

its me mario, it should be pin13 to GND. First trace where it heads to find a good soldering point. Measure default resistance between pin13 and GND.

Mean Machine, it should have that most common IC (uP62....) so it's easy to do Vmod...

[Mean Machine]

Great, thanks for the answer. I'm worthless at finding vmods myself, I'll have to start looking in to that.

A Sapphire HD4850 Dual-slot version ordered.

[its me mario]

its me mario, it should be pin13 to GND. First trace where it heads to find a good soldering point. Measure default resistance between pin13 and GND.

I just moved so I don't have a soldering iron. Any temporary pencil mods I could do?

thanks for the help!

[Nelson2011]

With the pencil mod for the non reference sapphire 4870 the vcore went from 1.32 to 1.34 lol

[its me mario]

Look at this bull sh*t!

http://www.evga.com/articles/00462/default.asp?gvt=1

me r mad

[Mean Machine]

I can't seem to find the UP6201BQ datasheet anywhere, if anyone could tell me where I'd need to solder the resistor I'd be grateful.

[ceemic]

Mean Machine, yes I know this datasheet can't be found. But it is basically the same as NX2420: http://ceemic.pri.ee/hardware/datasheets/NX2420.pdf
So pin13 is FB.

[mattkosem]

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!

This mod works great on the EAH4830 as well, since it shares the same PCB. Thanks!

--Matt

[ceemic]

mattkosem, nice to know

[Mean Machine]

Mean Machine, yes I know this datasheet can't be found. But it is basically the same as NX2420: http://ceemic.pri.ee/hardware/datasheets/NX2420.pdf
So pin13 is FB.

Thanks!

Just my last idiot question then, before I actually can start feeling like I've thought something right for the first time; just pin 13 to ground with a 100k VR and from there it's the regular stuff?

Sorry, I've just never had to think of Vmodding, since I usually don't really care about the graphics cards.

[ceemic]

Mean Machine, measure default resistance before moding! The resistance may vary through different layouts.

[Mean Machine]

Mean Machine, measure default resistance before moding! The resistance may vary through different layouts.

Of course, of course. I just took the 100k as an example as it's "default".

Big thanks for all the answers.

EDIT: Resitance between pin 13 and ground is 5.8kOhm, should anybody be interested.

[ceemic]

Then 100k VR works fine

[Nelson2011]

Where do you guys find your VR's?

[Mean Machine]

Depends on your country. I myself buy mine from ELFA, which seems to be available in northern europe as a whole.

[les_paulde]

Guys, I just wanted to say: THIS THREAD IS AMAZING!!!!


Thanks to you all, I've just successfully modded both my HD4850s, and they are currently running 770Mhz core @ 1.26v! These were cards that would not even do 660Mhz stable @ stock!

I guess there should be more left to push, so I'm hoping for an 800Mhz, 24/7 setup. I can't believe that 10bucks worth of equipment can make these cards run faster than an HD4870! Both in 3dmark 2006 (22423 points) and Vantage (14914 points) I've currently got the highest scoring system for a Q9550 with 2x HD4850. I had no idea about how to do this mod, but as I have quite some soldering experience, I figured I should give it a go. Thanks to the clear instructions from this thread, there were no mistakes made and as I am watercooling them with a full-cover block, the cards' temps never exceed 45C (for the top card) and 49C for the bottom.

Here's a pic of my mod:


And the cooling:


Is it around 1.30v what most people have needed to get their HD4850 to ~800Mhz?

Oh and my Vantage screenshot: