Nvidia GTX 980 TI Cooling-Tweak



My System is pretty much styled out and my rendering runs on two Gigabyte GTX 980 TI G1 Gaming (SLI). Recently I've had problems with fan noise and higher temperatures than usual. My 4790K is overclocked to 5.0 Ghz and is cooled by a Lepa Exllusion 240 liquid cooling AIO. My case is the Aerocool P7 C1. The three 120mm fans in the front are sucking air in. The radiator for the CPU is mounted on top and blows out. The last fan on the backside of the case is blowing outwards too. Here you can have a look at my entire system which is the base for this tweak.

The problem:

I've got my GPU's since a little more than two years now and they ran really good. From one day to another, the fans started to emit a much more louder noise than usual and my maximum temperature of 83°C per GPU was always hit faster and more often. After checking the fans and applying new thermal compound to the GPU, i recognized, that some of them make noises and get blocked while spinning. A look at AliExpress confirmed, that i can get the fans for around 70$ in 21-30 days delivery time. I thought, that 70$ including shipping is pretty much for six 75mm fans that sound like a jet engine on 100% spinning. I took a look around my basement to see which parts i got left. Luckily a bunch of Bitfenix 120mm LED Green fans popped up. So i thought: "Okay, my fans are becoming louder every day and my temperatures are not that good anymore. I will mod my GPUs!"

The plan:

Creating a cooling that has better temperatures and less noise by exchanging the 3x75mm fans with 2x 120mm ones. Sure, a lot of the cooling performance itself comes from the sheer RPM of the little fans that are around 4500 RPM. But what about taking bigger fans, that have much less RPM? The thoughput of the 120s should be a lot more, so i can spare RPMs to reduce noise.

The prequisites:


Obivously, the first step is to dismount your GPU from the case. Please make sure, that the power cord is disconnected and if you have a power supply with a switch, that this one is disabled too. Loose the screws at the mounting frame on the front of the GPU first. Then disconnect the power cables for your graphics card. The last thing to do is to put the catch of the PCIe-Slot to open, so you can pull out the card soft and without force.

Further you have to dismount the graphics card itself. You can see, that a partner graphics card is pretty much always made out of four components. These components from left to right are: The fan cover, the heatsink, the PCB and the backplate. Start by removing the screws on the backplate. Around the Die itself are four of them, looking like a square. Try not to lose the springs attached to the screws. Three other, smaller screws are located more at the end of the Backplate. Once you removed all of the five screws, you're able to dismount the first stage. Grab the card between the fan cover with one hand, and with the other one on the backplate and try to spred them apart. Most likely, it will take a little bit of force, because the thermal compunt between heatsink and Die will have a vaccum-effect. The thermal-pads on the memory also are a bit sticky, thats the reason you need force.

Get yourself some cloth and soak it with the Isopropyl-Alcohol and remove the rest of the thermal paste on both sides, the Heatsink and the Die. Try not to touch the faces resting on the Die, because you have fatty, sweaty fingers, reducing your heat-throughput. No, you're not filthy, its just something everyone has :)

Let's take a in-depth look at the PCB itself. (Click the Pic to enlarge). On the outer left side we can see the Die of the GPU with new thermal paste applied already. Left, top and right of it, we can see the memory modules (four on each side), containing 512 Megabyte of space per module (12x512 MB = 6GB Memory). They are covered by the "white-stripes", they're the thermal pads. Left of that you can see two rows of black parts. These are the capacitors, stabilizing the current for the processor. The row left of them are grey MOSFETs, providing the multiple power phases for your chip. Top-right we see the 2x8 Pin connectors from the PSU to supply your card with actual 12V+ power. Now we go to the red circles. The top-left one shows two pins. They switch the "Stop" and "Silent" Logos on the Windforce-Panel. The top-mid circle shows 4 Pins connecting the RGB-LED fot the Windforce-logo itself. The bottom-right one shows 4 Pins also, but this time we know, that these are the fan connectors with PWM-signal.

Take a look at the pinning of PWM-fans on the picture. We see, that Pin 1 is ground, which means, that there is negative current. The second Pin provides positive current with a maximum of 12V+. Pin no 3 is Tacho/Signal/Sense, which means, that it reads out the speed of the fan. The last Pin is PWM/Control, meaning that it provides a PWM-generated rectangle-signal used to control the fan speed.

Here you can see the connectors of a standard RGB-LED. Either you have common Anode, or common Cathode. For the different lights, you need different resistors, shown in this picture. If you light up all colors, you'll get white. But other color mixtures are possible too, like red and blue giving you purple. So much in theory for the Windforce-Logo.

Next, we compare the plug of the PWM-Fans from Gigabyte to the one, provided by our Bitfenix. As we can see, they're both different size. The Gigabyte one is smaller and in the right side between my fingers. The big black one is the one from the fans we want to mount. Because we want everything to fit as perfectly as possible, we have to cut both and connect the little one to the cable of the Bitfenix fan. We do that by soldering it together. But firstly, let's not forget that this connector has to supply two fans and not only one. So we'll create a Y-switch to power up everything correctly.

After we cut the cables, we strip the isolation away for like 1 cm or a little more. Then we plug in and heat up the soldering iron. Take a little bit tin and cover the striped wire ends in solder. After you have done that, you can connect and solder the three cables altogether, but make sure, that you connect the right pins to each other. Otherwise your fans will not run, causing your GPU to shut down, denying thermal destruction of itself. In my case, pin one had white stripes drawn on the isolation, so i knew that has to be ground. If you are not sure, take a 12 V power supply and test the correct wiring. At this stage of the mod i had to believe, that Gigabyte uses the standard wiring for PWM-Fans. If you are highly doubtful, you can take an additional scope and measure the Tacho/Signal/Sense pin which is the third one.

After soldering it all together (Two fans, each four wires + the connector from Gigabyte), make sure to use tape to isolate the wires apart from each other. If you really want to make it good looking too, then take a thermal shrinking tube before soldering and apply heat on them afterwards. They will shrink to a smaller size, protecting your soldering perfectly from other conductors.

Take a 12 V power supply at least now, if you haven't already, and do a test run. If you did everything right, your 120 mm fans should run on full speed. If they do not, but your pinning and soldering is not the issue, then take your Multimeter and measure the resistance between the soldering to make sure, that everything conducts well. You can learn how to setup and use a Multimeter pretty much everywhere on the web. Just ask google.

This step can be optional, if your fans do not have LED on/off switches. After all that we want to support the cards functionality of switching on/off the LEDs named "silent" and "Stop" on the Gigabyte Windforce panel. We use that two pins output mentioned earlier (on the PCB overview) to turn the green LEDs of our fans on and off. To do that, we simply have to solder the LED switches from the fans together to the Gigabyte connector. So, all in all this step is pretty much the same one as the last one. Like said: Do not forget to isolate every wire pretty good. Either with tape or with shrinking tubes.

By no later than now you really have to put on new thermal paste on top of the Die. Do not take too much or too less of it, because both situations are leading to minimized thermal connection between the Die and the heatsink. You can apply the paste either with a spatula, or with latex gloves. It's up on you, if you want to cover the entire Die, or let the pressure from the heatsink do the distribution of the thermal paste across the Die.

Now we prepare to mount the fans on top of the Heatsink. To do so, do not forget to connect the LED switch (Two Pin) on top of the PCB and the fan connector (Four Pin) to the bottom of the PCB as mentioned. After you plugged both in, you can start to distribute thermal glue to the center of the backside of each fan. Be careful by choosing the final position, because other parts like SLI-Bridges or capacitors on the mainboard may get in your way. Look for that in advance to not receive a an evil surprise. Press the fans from the top on the Heatsink for like a minute. Continue with checking the cohesiveness of the fans to make sure, they are glued well and they don't go for a walk.

We reach the finale! Yaaay! Take the wires, that are maybe too long and look for a nice place for them to live in. Make sure, that the fan blades don't hit them and watch out that they are not blocking anything else moving. If you're ready for take-off, mount the GPU's back in your case. If you got an SLI build, do not forget to mount the bridge again.

This picture shows the first modded graphics card back in my case. As we can see, the card is now a little bit higher than with Gigabytes cooling. After all I did not have any problems fitting the mod inside my case, because i was always are about the shape change of the card. Always had one eye to the expected positions and you should too.

Alright, alright, alright, FIRE 'EM UP!

Some last words: Again, I'm not responsible for ANY damage done by this mod or while executing it! Before you mount everything really nice and tight again, do a test run. Power on your PC but take a look at the fans spinning immediatly! If they do not spin, there is something wrong and you might have the danger of destroying your lovely GPU! Let the test run continue until the first few Benchmarks of your choice are over and always have an eye on the temperature! You can read it out with several freeware software, downloadable from the web. If you feel good and everything went without issues, you can beautify your build again. One thing i really have to emphase is, that while benchmarking the Gigabyte fans really can sound like a jet engine or a vacuum cleaner. The mod itself is MUCH LESS noisy, i did not expect that much change, but it is reality.

Temperatures, noise and conclusion:

Fans:  3 x 75 mm fans @ 4500 RPM max

 2 x 120 mm fans @ 1600 RPM max

Noise: 25 dBa

12 dBa


Idle / Desktop / 2D 42°C 26°C
3D Mark Time Spy 81°C 72°C
Furmark 83°C 83°C
Heaven Benchmark 81°C 69°C
The Division 83°C 73°C
DeusEx Mankind Divided 82°C 74°C
World of Tanks 83°C 69°C


Test system: ASRock Z97 Extreme 4 3.1, Intel Core i7 4790K (delid, liquid metal) @ 5.0 Ghz, 4x4 GB G.Skill Ripjawz 2133 Mhz, 2x Gigabyte GTX 980 TI G1 Gaming SLI, Corsair A-135 Series 850W PSU.


The Benchmarks were either default (3D Mark) or Ultra (all others) with a resolution of 2560x1440.