ATI Radeon 9700 Voltage Modification
Date Written: October 5, 2002
C. aka Chong345
With the release of the Radeon 9700 obviously the hardcore overclockers would
be looking for any way to squeeze all the juice out of it. Thanks to DDTUNG over
he was instrumental in figuring out exactly how to voltage mod the 9700, and here's an article on how to perform
it without soldering on the card. Please read the whole article to get a better
understanding before you attempt to do anything! We are not responsible
if you kill your video card!
- Radeon 9700 (of course)
- 10k Variable Resistor (Potentiometer)
- Soldering Iron & Solder
- A Length of Wire (30 Gauge Works Well)
- SMD Grabber
- Fan Tail or Similar Connector
You can find most of these at a local electronics store. I had a hard time
finding the SMD Grabber, but I got lucky while just browsing at Fry's
Electronics. There are a few places on the Internet where you can order SMD
Grabbers if you can't find a place local. The rest of the items should be very easy to
find, that is if you don't already have them laying around the house.
Okay the first thing that you need to do is identify the chip we will be
modifying, it's the SC1175 on the back of the card. The chip should be right by that
big silver plate, please note the orientation in the picture. Pin 18 on the chip
is the pin where the SMD grabber will attach. When we
are finished pin 18 will have the SMD Grabber attached then to it a wire that
goes to the resistor, then from the resistor to a fan header on the motherboard,
which will serve as a ground.
So first we need to decide on how much wire we will need. So get an idea by
measuring out the distance from the IC Chip to the Fan header you will be using.
The reason for using a fan header is because it allows you to remove the voltage
mod completely from your system, and also doesn't require any soldering on your
motherboard. There are many other points you can ground to, like your case, or
the ring on the motherboard where you put a screw through. When you are
measuring wire, give yourself a little bit extra for good measure. Strip off a little bit
of the wire covering on both ends so that the wire is exposed. Next solder the
wire to the SMD Grabber, there is a terminal inside of the grabber you can
solder to. Next solder the other end of the wire to one of the furthest right or
left leg on the potentiometer. Now take the fan tail and we will use the wire
from this as a ground.
So you can cut all the other wires except the one that
serves as a ground. Leave yourself about an inch of this wire. I just used an
old reset connector from an old case I had. It still served the same purpose.
Now solder that wire from the fan tail to the middle leg on your resistor. You
will need to pre-set the potentiometer before you place it on the card. Use a
multimeter to see what the resistance value is. You can change the resistance by
adjusting the potentiometer. 8000 Ohms should give you close to 1.6v on the core
of the GPU. This is a good place to start especially for air cooled cards. Heat
is going to be a big factor. As of when this guide was written, Danger
Den makes the only water block for the Radeon, however Swiftech
should have one out shortly (in both regular & pelt cooled), as for
aftermarket air-cooling, you are SOL for right now. You don't want to fry your card from having too
much voltage. Remember that the lower the resistances the higher the voltage
will be. As you lower the resistance, electricity will drain off through your
mod which makes the feedback circuit think the voltage is lower than it really
Once you have everything soldered together, and are sure the resistor is set
to 8k Ohms, use the SMD grabber to clamp onto pin 18 on the Radeon, and connect the fan tail on a fan header on the
motherboard. Make sure you did everything correctly and that you are using the
proper pin on the fan header.
Now that you have double checked everything its
time to power on and see how the mod went. Get out your multimeter and turn on
the computer. Place one probe on a ground somewhere and the other on the spot
specified in the picture. We are measuring for voltage this time and not
resistance. You should be getting about 1.6V if you used 8k ohms. The point you
want to measure is a solder pad directly above the m in
"Complies" that is printed on the PCB.
Be sure to
monitor temps at all times. First see if you can overclock any higher from you
last maximum prior to the volt mod. If you can go higher then max it out until
it becomes unstable again. Once
you are overclocked to the max, again up the voltage some more by lowering the
resistance. You can do this while your computer is on so you can get a reading
as soon as you make the adjustment. I must emphasize, go in small increments.
go in .025v increments. You can choose whatever you like but be careful. It is
helpful if you have a second set of hands to monitor the voltage while you
adjust the resistance. Once you adjust the voltage, again see if you can
overclock any higher. Basically repeat this process until you are
totally maxed out for your cooling, voltage, or whatever. Then it's up to you
where to go from there.
Once again, a special thanks goes out to DDTUNG and the guys over at XtremeSystems.org for
discovering the voltage modification.
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