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- Mar 27, 2005
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- Fresno, CA
Video Card Volt-Modding Guide
The following is intended as a step-by-step guide for doing a voltage modification on your video card. (Also known as a volt-mod or v-mod.). Let me start with a basic intro. . .
V-modding a video card is simply the act of altering the electronics on a video card so as to allow a user to manually adjust the voltage that specific components on the video card receive -- usually the Graphics Processing Unit (GPU) and the video RAM (memory). Doing a v-mod typically consists of soldering a variable resistor (with specific value) to a location on the video card that will allow the voltage on the GPU or memory to be adjusted. This will typically allow for higher stable overclocking (provided proper cooling is used). For tips and techniques on soldering electronics in general, the following are great references:
Tiny soldering - How I do it (from OC Forums)
Voltage Modding Guide (from VR-Zone)
The guide I am presenting here contains specific tips and techniques that I have found to be useful specifically for v-modding video cards. This is simply the method that I personally use but of course it's not the only way. With that said, I think this is probably an appropriate place for the usual disclaimer, so here it goes. . . .
Please be advised that volt-modding comes with great risks including the risk of destroying your video card and voiding the warranty from the manufacturer. I am not responsible for any damage or loss associated with the use of this guide. Use it at your own risk.
Ok, with that said, let’s get to v-modding. First you need to make sure you have all the proper tools/supplies. Here is a list of what you’ll need.
Supplies
1. A soldering iron.
You should be able to use a 10-30W soldering iron available for $8-12 at Radio Shack. (link) Make sure to get one with a stand to rest the iron on. It is also ideal to use a micro tip but it is not necessary. I would suggest at least using a brand new tip or one that has been filed down. (If there is a lot of old solder or debris on it, this will make the job much more difficult.)
2. Solder.
You want to use a small diameter solder rosin core like 0.032” (link)
3. Variable Resistors.
(These are also known as VRs, trimmers, potentiometers, pots, trimmer pots, etc.). These need to be of the proper value as indicated by the v-modding guide that you use. Radio Shack has a very limited variety. You can find whatever value you need at mouser.com or hosfelt.com.
4. 24-26 gauge wire.
This can be found at Radio Shack. (link) You may have to buy a full role with about 20 feet (far more than needed for a single v-mod). But it’s only about $5 and you can keep it around for future v-mods. You do not want to use wire thicker than that as it will be more difficult to solder to tiny points.
5. Heatshrink.
This can be found at Radio Shack. (link) You’ll need this to cover bare connections.
6. Needle-nose pliers.
The smaller the better.
7. Wire stripper
This can be found at Radioshack or any hardware store. (link)
8. Digital Multi-Meter (DMM).
You will need this to measure resistances and voltages. It is highly recommended that you use a digital meter which will allow you to have more accurate readings than an analog meter. You should be able to find one suitable for this work at no more than $20. (link)
9. Helping Hands.
This can be found at Radio Shack (link) This is not mandatory but highly recommended. Without it soldering can become a juggling act as you attempt to hold the soldering iron, a VR, a wire, and the solder all at once.
10. Conformal coating, superglue, or some other adhesive.
I personally use conformal coating from DangerDen.com. But any adhesive that can be applied to electronics should work fine.
11. A female molex.
You can either order one of these or just clip it off of an old fan or adaptor/extender that you don’t need.
Procedure
Ok, so with all the tools and supplies, you should be ready to do the v-mod. The following is a step by step guide that should prepare you and guide you through the processes. I’ve tried to include pictures wherever I thought they would be helpful. (They are pictures of me v-moddding my 7800GTX.)
1. Research the v-mod online.
The first thing you need is a specific guide for the particular card that you are modding. You can check this list to find a quick reference on your specific card. Look for a v-mod for altering the GPU voltage and the memory voltage, and also points for measuring the voltages. Also find out the values of the VRs that you will need.
I personally recommend doing some extra research to also find out the results other people have had with the specific v-mod that you will be doing. This should help to avoid making mistakes that others have made and also to find out important things like the maximum voltages that people have used, the speeds you can expect, and the temperatures you can expect. To get as much information as possible,, you can go to the v-mod section of each of the overoverclocking forums that you know and do a search for your particular card. Here is a list of the v-mod sections from some of the popular forums: xtremesystems, extremeoverclocking, vrforums, insanetek, and of course just search in google.
Please be warned, however, that some people may reports v-mods, resistor values, voltages, speeds, and other information that are not correct. So it is important to carefully consider what information is trustworthy. Also note that the if the card is very new, it is possible that the v-mod points have not been determined for it yet.
2. Print out the diagrams and pictures that you find and match them to the card.
Once you have decided which guide and pictures are the best to use, then print them out for reference. Have the card handy in front of you and start to match it with the pictures and guides printed out. Make sure to properly identify all the points where you will be soldering.
3. Plan where you will be placing the variable resistors.
You want to use the shortest leads possible from the variable resistor to the soldering points on the card. Some experienced v-modders (such as Viper John) prefer to place the variable resistor right at the solder points. (Like this for example.) This is considered ideal to avoid the EMI (electro-magnetic interference) that is caused by wires running along the card. However, this method can also make it dangerous to adjust the VR because it requires reaching in with a screwdriver to adjust the voltage while the system is running. If the screwdriver slips and makes contact between the wrong two points on the card, it could short out the card and kill it instantly. So I personally prefer putting the variable resistors on the edge of the card in a setup like this. That makes it easier and safer to change the voltage while the system is running.
One thing to note here is that sometimes a v-mod will require the heatsink-fan to be removed in order to have access to the points that need to be soldered. If that is the case, then carefully remove the heatsink. However, if that is not the case, I would recommend leaving the stock heatsink on the card, even if you are planning to water-cool or TEC-cool the card. The reason is because if the volt-mod should fail or harm the card (God forbid!), then you wouldn’t want to have to go through the hassle later of removing the water-block, TEC-block, and even RAM heatsinks. So leave the stock heatsink on if possible and use it to just test that the card still runs after doing the v-mod.
4. Plan to include a female molex for measuring voltages.
It can be dangerous to measure voltages on the card while it is running for the same reasons just stated above (the voltmeter probes can slip and make contact between two points causing a short and killing the card). For this reason, it is a good idea to include a female molex on the edge of card that is soldered to the points where the voltages will be measured. A female molex should be used rather than a male because it is easy to insert the probes of a voltmeter into the holes of a female molex. You will need to solder one lead from the molex to the GPU voltage reading point and one lead to the VDD voltage reading point. (Some people also solder a third wire from the molex to a grounded point on the video card but I don’t think it’s necessary since you can ground the DMM to the case when you’re taking voltage readings.)
Here's an example where I planned the location of the VRs and female molex. (Note: For each thumbnail below just click on "Link" to see the full-sized picture.)
Link
5. Adjust the VR values.
The first thing you need to do before soldering the VRs is to check the resistance that they are set at. There are three pins (usually labeled 1-3). But you will only need to use two of them. Either use pins 1&2 or 2&3 (in other words, make sure not to use the two outside pins which are 1&3 or you will not be able to vary the resistance later). I recommend that you turn the knob of the VR completely counter-clockwise until the maximum value of the VR can be measured between pins 2&3. Then clip off pin 1. By doing this, your VR should be setup so that if you turn the knob clockwise, the resistance will decrease and thus the voltage will increase on whatever component you solder it to. This way the VR will be much like the knob on a fan controller, turning the knob clockwise gives more power, and turning it counter-clockwise gives less power. (It’s just easier for me to remember later when I’m tweaking the voltage on my video card.)
Here's an example of a VR with pin 1 clipped off.
Link
Something to note here is that you will not be able to check the value of the VRs later when they are soldered on. Even if you test the resistance between the points where the VR is soldered on, it will not give you the resistance of the VR. It will give you the TOTAL resistance between those points which includes the resistance in the circuitry of the card. So make sure that you have checked the values of the VRs carefully before soldering them.
6. Cut and strip the wires.
Plug in the soldering iron so it can start to get hot. Place the VR on the video card where you plan that it will be. Measure out the wire needed to reach from the VR to the v-mod point on the card where you will solder. In general, you want the wire to end up laying as flat as possible against the video card (rather than hanging sort of loose) so that it doesn’t accidentally get pulled off later. So run the wires between any chips, capacitors or resistors on the card rather than going over them. Also remember to orient the tip of the wire so that it lands right on the spot where it’s going to be soldered on the video card. If the spot on the card that you are going to solder to has some circuit elements near it (resistors, capacitors, etc.) then try to run the wire from the opposite side from those elements to avoid getting any solder on them and accidentally bridging them together. Bend the wire into whatever shape necessary to accomplish all of this. You can use the needle nose pliers to bend the wire into a sharp L-shape wherever necessary. Once you are satisfied with the way the wire will sit on the card, cut the wire with the length needed. Take the wire and strip both ends suing the pliers to hold the wire and strippers to strip it. Only strip a tiny tip (about 1/8”) of one end for soldering to the card. The other end can be stripped a little more (about 1/4”) for soldering to the VR.
7. “Tin” the wires.
Put each wire in the Helping Hands one at a time and “tin” the tip of the wires that will be soldered to the video card. In other words, melt a little bit of solder on the tip of the wire. This will be used to connect it to the video card later. Make sure not to put too much (like a big glob) or it could cause too much solder to end up on the card later. But also make sure to put enough so that it will make a strong bond. It should end up looking like a little silver, pin needle tip on the end of the wire. Do this to each wire.
Here's an example where I was tinning a wire using the Helping Hands
Link
Here's the wire after it was tinned.
Link
8. Attach the wires to the VRs.
Cut a portion of the skinniest heatshrink so that it’s about the length of one of the pins of the VR. Thread the wire through it. Put the wire in one of the clamps of the Helping Hands and the VR in the other. Brings the arms of the Helping Hands together so that the bare tip of the wire overlaps with the pin that you will be soldering to on the VR. Hold the solder over the connection and melt it over it. Don’t use too much solder which makes the connection clumpy, but also don’t use too little or the connection will be weak. Once it seems solid and smooth, you can take the wire and VR out of the clamps, turn them over, put them back in the clamps and repeat the process to get the other side. After the connection is completed, move the heatshink over the connection and lightly heat it up with a lighter until it shrinks. Be careful not to burn the wire or heatshrink. Do this for both wires that will be attached to the VR. You will need to do steps 5-8 for each VR you are going to use (for example one VR for the GPU and one for the memory).
Here's an example where I lined up the wire and VR pin to be soldered.
Link
This is what it looked like after being soldered.
Link
This is what it looked like after heatshrinking the joint.
Link
9. Prepare the female molex for soldering.
You will need to do a similar procedure for the female molex that will be used for the voltage measuring points. If the molex has fours wires, pull out two of them (perhaps the middle two) that are not needed. Place the molex on the video card where you plan to attach it and figure out how to run the wires from the molex to the voltage measuring points. Clip the wires and strip the tip (again only about 1/4”). (As mentioned above, some people also solder a third wire from the molex to a grounded point on the video card. If you choose to do so, then keep three wires from the molex.)
10. Glue the VRs, molex, and wires to the card.
As mentioned before, I use conformal coating to do this but there are other options as well listed in the supplies above. Again, make sure to orient the wires in a way that puts the tinned tip right at the soldering point (yet away from other components) and also make the wire lay flat on the card. Glue it down at a few locations (preferably on the bare PCB rather than over other components.). Also glue the molex and VRs to the card. Do not use too much adhesive in case you later need to remove it or clean the card (perhaps to sell it). However, make sure you use enough to keep the wires, VRs and molex securely in place. Remember that you will be applying some torque to them later when you turn the knobs of the VR or place a DMM probe in the molex. So they need to be secure. Wait about 30min. to an hour to let the adhesive dry. You may need to hold the wire down or the VRs and molex in place if they keep moving until the adhesive gets a little more dry.
Here's an example where I was holding the wire in place that I would glue down.
Link
I personally recommend using the adhesive before soldering the wires so that you can place the VRs, molex, and wires exactly where you want them without accidentally breaking the soldered points later. You can also get the tinned tips of the wires to sit secure right at the points where they will be soldered which should make it easier to solder them.
11. Solder the wires to the card.
One the adhesive is pretty dry proceed to solder the tinned tips of the wires to the video card. It should only be necessary to heat up the tinned tip of the wire until the solder melts down a bit and makes contact with the video card. Look closely and make sure that the connection is made. If for some reason the connection is not done right (for example, the solder beads up and comes off the connection) then it may be necessary to apply a little more solder. It is preferable not to do this, but sometimes it’s necessary. If so, take the solder and melt just a tiny, tiny bit over the sold point to secure the connection. Once the connection is made, you can also put a dab of adhesive over the solder point to ensure that it stays secure and doesn’t get pulled off on accident later. (Or you may want to do this after you’ve tested the card because if the join needs to be resoldered, it will be a lot more difficult to work on with adhesive spread over it.)
If something happens that requires removing the wire completely from the soldered point, DO NOT JUST PULL THE WIRE OFF THE SOLDERED POINT. There are so many cases of people who hastily remove their v-mod by just pulling the wires off and end up yanking a resistor or capacitor off of the card as well. The proper thing to do is heat up the joint until the solder is softened and then careful remove the wire. There are also desoldering tools available for this purpose as well.
Here's the result of my own v-mod.
Link(To see more on the results of this v-mod, look here.)
12. Test the card.
Now comes the moment of truth . . . testing the card!! . . . After installing the card, I recommend checking one more time that the VRs are turned for maximum resistance. If you used the instructions in step 5 of this guide, then that means the knobs of the VR’s should already be turned completely counter-clockwise. Also, place a probe of the DMM in the molex to measure the GPU voltage and set the DMM to “2V” so you can get a proper reading of the voltage. Ground other probe either to the case or a ground point on the card. (Make sure you DON’T SET THE DMM TO MEASURE CURRENT, this can cause a short circuit and kill the card.) When you turn on the system, watch the DMM so that you can immediately see if the voltage jumps too high. You might be able to save the card by turning of the power immediately. And finally . . . hold your breath, say a prayer, and hit the power button. . . .
Final note:
Hopefully you are rejoicing over your successful v-mod at this point. Just remember that with more volts (and higher overclocking) comes much more heat. So make sure to use proper cooling. I wouldn’t recommend v-modding at all unless you are using water-cooling, TEC-cooling, or very high end air-cooling.
Also, it is recommended that you adjust the VRs very slowly and test the system for every 0.01V-0.02 increase, on the GPU or memory. The less voltage you need to achieve a stable clockspeed, the better for your card. Make sure to compare and ask around about the voltages, speeds, and temperatures that others are getting. . . . And most of all, have fun with your new v-modded card.
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