An advanced mod to increase performance. — Stilian Rakovsky
Disclaimer: Neither the Author or Overclockers.com takes any responsibility for any damage if you attempt what is shown here. This article is for information purposes only.
After I read and learned many things from Overclockers.com, I decided to write this article and send it to Joe :).
Yesterday I VModded my MX400 card successfully and now I will explain how:
First, I read Xbit labs article about GeForce2 GTS/MX VMod, where I found info about the microchip responsible for the core voltage (US1150). Luckily, the same chip was also on my MX400 card from Asus.
Things that are needed:
- 100-120Ohm 1/4Watt Resistor
- Good Cooling
- Soldering Stuff
- Fan Header
The VMod now is ready to start.
A microchip manufactured by UNISEM labeled “US1150” is the voltage regulator:
A 110 ohm resistor must be soldered to Pin 1 and Pin 2 on that chip. Here is a “smart” way how to do that:
Here is a diagram of my VMod:
I soldered a Fan Header, so later I can easily turn the resistor on/off .
Before the Vmod:
R1 = 97Ohm
R2 = 59Ohm
Vout = 2.01V
After the Vmod:
R1 = 51.5Ohm (1/R=R1+R2/R1*R2 => R=R1*R2/R1+R2 => R=97*110/97+110 => R = 10670/207=51.5Ohm)
R2 = 59Ohm
Vout = 2.68V
VREF = 1.25V
IADJ = 50uA (0.00005A)
Asus Smart Doctor doesn’t show the right voltages, :(, so you must use a Multimeter!
The core voltage went up from 2.01V to 2.68V after the mod. I can O/C my Asus V7100Pro card now up to 285 MHz core clock (100% stable).
My MAX Core Temps are 45C under Full Load. I use an old Spire (Speeze) CPU Cooler (5C11B3) for the GPU. Also during the bench, I put one 120mm Papst fan near the video card. (Room Temp: 16C it’s very cold this winter 😉 )
Before VMod (2.0V): 265MHz @ 36.5C
After VMod (2.5V): 285MHz @ 45C
Performace Increase in 3DMark 2001:
Asus V7100 Pro O/C @265/280: 3760
Asus V7100 Pro O/C @285/280: 3873
- CPU: Duron 7×155
- Asus A7V133
- 256MB KingMax PC150
- Detonator 22.40
Good Luck !