ATI 4850/4870 voltmod thread

[Gestler]

Vmode done ... a special thanks to the user borec (Slovakia) from my home forum. Whether the benefit of all

[ceemic]

Pin 6 is FB?

[Gestler]

Yes!

[Solarfall]

hey Gestler how much more have you been able to push your card on air/ water after that mod ?

[Gestler]

The card still works with the original cooler, water will be next week, 1.47 V = 1GHz stable 1.53 V = 1.1 GHz stable but the card is critical overheating.

[borec]

nice result for air cooling MSI VGA card are very good

[Gestler]

Maybe just a good piece, otherwise the card is made very cheaply, we'll see how long it lasts

[overclocking101]

ceemic do you have pics of anymore of your vmods?? like indexed like your hd4850 ones?? ive seen more around the forums and your work is very nice. sorry for the off topic post guys

[ceemic]

overclocking101, all my mods are here: http://ceemic.pri.ee/hardware/

[Gestler]

Pencil Vmod for Ram/4890 MSI Cyclone
Great thanks to the user borec (Slovakia)

[arroyo]

overclocking101, all my mods are here: http://ceemic.pri.ee/hardware/

It's hell of a lot of good photos. Lots of cool ideas. Thanks.

[Gestler]

overclocking101, all my mods are here: http://ceemic.pri.ee/hardware/

Great work

[overclocking101]

i have the powercolor HD4870 with the analog V-regs on it not the tandard design the non refrence design PCS+ can someone point me to the Vmod for it??

[ceemic]

overclocking101, pictures please

[overclocking101]

ok will take some asap

[overclocking101]

ok here they are :

[ceemic]

overclocking101, NCP5388? http://ceemic.pri.ee/hardware/hd4850gs/
http://ceemic.pri.ee/hardware/datasheets/NCP5388.pdf
Measure def resistance between pin19 (FB) and pin14 (or any GND).
PS. Don't forget to remove the card from PC before. You should have done this before taking pictures also

[overclocking101]

yep thats the chip ill pull the gpu out tonight and post measurements

[overclocking101]

well ceemic i can seem to pull any measurement off it at all

EDIT 16.31 kohms

[ceemic]

overclocking101, if You are 101% right, then use 250k VR + 100k resistor in series. I used 100k VR on HD4850 with same chip and def resistance was definitely below 10k ohm.

9 times measure, 1 time mod

[overclocking101]

ok ill measure again the chip orientation is a bit weird its backwards on the gpu

[Meusi]

@gestler

thx for your Vmod!!! I tried this mod also successfully. I prefered a 50k spindle potentiometer using fan-GND.
a 20k delivers 1,47V with highest resistence.
My cyclone OC runs with 1,45V@1000/1100@82° still pretty quiet.
The heatpad between GPU and Cooler is a chewing gum, it should be replaced.
lowers the temp about 10°C to 20°C.

Meusi

[devil_mcry]

Is possible with rbe change voltage over 1.158v on hd4850?

My 4850 1gb Sapphire is stable @ 750mhz 1.158v with furmark renamed extreme burn test... is it good or normal?

[drizzt5]

I did the pencil mod once again after a long break (I was using a vmodded 8800gt for a while).

My temps appear good... Nothing on the 4850 itself goes above 49C's according to GPU-z and the voltage at this moment in time is 1.356 I believe using the first pencil mod. Right now I can clock the core between 820-850 it appears. I am moving it up 10mhz slowly so I will have a solid number soon.

My question is how high should I go with voltage? I would prefer not to kill the card but I am interested in 900 on the core.... even if it is only for benchmarks (but if I can game with it even better!). I am going to do the 2nd pencil mod pretty soon

I'm at 840mhz right now stable. I've been testing with a few races of GRID :P
nvm, 830 is the highest with current voltage.

[JULO]

That's my first post, so I say Hello to everybody

I've done soldering vmod using W1zzard's method.
Here are the results:









and after suggestions from fellows from my home forum, I've added a cable ended with a crocodile to measure vcore





http://www.techpowerup.com/gpuz/cfeyc/
that's 940mhz @ 1.35V , at stock voltage this card did 710mhz

Does anyone know how to go through Riva Tuner's 940mhz limit?