The first GeForce FX 5800 Vmod

[berkut]

Hi guys

I believe that this is acctually the first Vmod for a GeForce FX 5800 in the world... If im not right please correct me and give a link


In my card there are 3 interesting voltages, the 2.5V (stabilized by 4 caps), 1.25V (for the vpu) and 2.65V...

I belive that the 2.5V is for the memory and 2.65V is for the Vref but again if im wrong please correct me ^^

This post coveres the Vref (i believe) mod and is very nice to do as its a pencil job just like Vmodding the Vdd on an NF7S...

The first thing we have to find is the proper resistor, here it is:

[berkut]

Now take a nice sharpened pencil and draw very, Very, VERY delicate its side, one line should increase the voltage from 2.65V (in my case) to 2.7V, the next few lines (always draw one line very gently) should increase the voltage to max 2.8V (in one of my forst experiments ive accidently increased the voltage to 3.2V ) as anything above 2.81-2.83V causes lock ups when changing resolutions and going in to different modes (2d-3d)..

Results of this Vmod... Before my 5800 non ultra would clock @ 590 core/ 1020mhz memory with stock ramsinks (straighten up and mounted with screws) and a Volcano 7+ on the core, cooled with 2x 120mm 38mm sunon fans, now it hits 590/1100 easyly....

Currently im working on the Vddr and Vcore mod...

[saaya]

nice! :p

[berkut]

Ok guys, some harddata in a moment, ive played a little with the datasheets and stuff so well be able to be more scientific and some professionals will kick in

[berkut]

Ok, lets start with my very first Vmod...



Here you can see the chip spec's for the Voltage reg near the Dsub



Heres how it supposed to be connected...

Here are the resistors to be hacked with a pencil (as i said earlyer- VERY GENTLY AND STEP BY STEP)



To be serious i dont know what this Vmod changes, is it a Vref or smth like that- changing the red marked resistor increased the mem o/c from 1020max to 1100... Didnt try the purple resistor...

Ok, now for the second Vmod...

First the pin layout:


If anyone with a Geforce 4 or a geforce fx can verify the image please do, i dont know if i marked the pin layout correctly, it maybe upside down

Ok, to the cheats:


The blue mod is acctually from a different topic from these forums and the 200kohm resistor was used there and it worked ok...

Now the Vcore mod (i thinkt the hardest):
The pin layout:


Youll have to find the Vid pins their resistors ^^ Than you have this table:


Here you can see how should you adjust the Vid's ^^ I believe that the Vcore is controlled by the bios of the card so youll have to hardwire it. As you can also see the max voltage is 1.55V but i dont think youll want to give more on a 0.13mik chip ^^

[berkut]

Didnt try this mod, its only a theoretical overview, ill try them when ill pass al the exams in sholl

Hope this helps everybody

[berkut]

Im just plaing with a Leadtec A300TD... CRAP....

both fx'es are non ultra but mine is a ultra from the pcb and elements, the leadtec is a J rev. and mine is H.. it has also 1.8ns mems but they o/c as hard as mine

and for the o/c... my god..

The gpu clocks at max 560mhz @ 1.55V :O (the card runs @ 1.25 in 2d mode and @ 1.55 in 3d :O), mine does with the same cooling 630mhz @ 1.35V
Mems clock @ 1030mhz but ive measured the voltages and they are ~ 0.1V- 0.15V higher than in my card... and still only 10mhz more than in mine...
Crap crap crap...

[Coolzero2k1]

nice!!! I'll get my fx5800 next week!

[berkut]

oh and btw ive got a prolink ^^

[Sakeo]

berkut, is there any way you post pictures back again... I would need them

[Snigel]

Yes I would really need them too. Please repost them.