Modding my graphic card with Noctua fans

Intro

This post will document how I swapped the stock fans on my Asus GTX 970 Strix graphic card with some Noctua NF-A8 fans. The result is kind of surprisng and I hope this will help you with your decision whether or not you should do it on your graphic card.

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My beloved GTX 970 Strix


Background

I bought this card in October 2014 and from the first day owning this card, the card has always been giving out this 'uneven' noise that gave a sense of something was shaking and unbalance on the card. You can hear it with the audio samples below:

These audio clips was recorded with a Rode Lavalier mic placed 30cm away from the CPU casing. Volume was boosted to better reveal the sound signature of the fans. You can gauge the actual sound level by comparing the sound of the mouse click to your own mouse click.

To be honest, the noise made by the card during gaming was not really that annoying. This could be seen from the fact that I only chose to swap out the card after 3 years of usage.

However, there were 2 reasons that I go ahead and swap the card, the first was this video from Linus Tech Tips:

The second reason was the fact that I got 2 NF-A8 PWM fans lying around in my tech cabinet. These 2 fans were originally bought for a case mod/design that I came up with, but it never materialised due to the high cost of prototyping the case here in Singapore.

To not left the 2 fans underutilised as well as fix the fan noise issue on the Strix. I set out to replace the stock fans on the graphic card.


Tools required

  • Set of standard Philip screw drivers.
  • Something to clean out old thermal paste, like towel and IPA.
  • Thermal paste.
  • Simple electrical tools to cut and strip out wire. Soldering iron is good to have to reconnect wire. Some electrical tape will also be needed.
  • Cable ties.

Things to note

WARRANTY

Carry out this mod will most definitely void your warranty. I'm doing this to a 3 years old card that is no longer covered. Do it at your own risk :P

EXPERIENCE

You should be familiar with PC electronic before carrying out the mod. Basic PC building experience is required as well. Basic aspects such as ESD, electrical safety, mechanical safety should always be observed during the mod.

REPLACEMENT FANS

Before you start, check if the graphic cards fans and your replacement fans are of the same type ie. PWM or DC and voltage. This will decide how your fans operate and how its speed is controlled.

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  • For my Strix, they are using PWM control. You can tell by the amount of wire that each fan is connected to.
  • PWM fan will have 4 wires coming out of the fan hub. DC fan will have just 3.

THe process

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  • Start off by disassemble the heatsink from the graphic card PCB. This can generally be done by unscrew 4 screws that surround the GPU from the back of the card. Consult tutorials and guides if you are not sure how to get the heat sink off the card.
  • Gently lift off the heat sink away from the card.

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  • Proceed to separating the heat sink itself from the fan shroud. This can be done by undo a few screws that attach these 2 components.
  • Remove the original fans out of the shroud. Be careful not to damage the fans wire.

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It's a coincidence that the width of the heat sink fins array is exactly 80mm. This make the Noctua NF-A8, which measured 80mm x 80mm, to fit perfectly. You may want to check the size of the heat sink array of your card before choosing your replacement fans since you may find it difficult to mount big fan onto smaller heat sink.

  • Using cable ties, attach the 2 Noctua fans onto the heatsink itself. I just loop the cable tie through one of the fin and tighten it up.
  • You can secure the fan anywhere on the heatsink as long as it can stay secured. This depends on the shape of the fin itself, the ease of mounting the fan at that location and many other factors.

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This is how it looks after attaching the fans onto the heat sink.


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Source: http://www.pavouk.org/

Source: http://www.pavouk.org/

Now it comes to the most difficult part of the mod, connecting the fans cable to the existing connector. However, it was much easier than I thought. Both original Strix fans and Noctua use the same PWM wiring colour code, which make connecting the wire much easier than expected. Just connect wires of same colour together on each fan cable and you are done.

Linus in his video connect the fan directly onto the motherboard headers instead of reusing the graphic card fan header. I would not recommend anyone to do this since the fan speed won't be controlled by the temperature of the GPU. This may lead to overheating if the fans don't react based on GPU temperature.

However, if you are using the graphic card to power and control the new fans, make sure that the total power rating of the new fans is below the total power rating of the old fans. If not, it's better to power the card using motherboard fan headers to prevent damaging the fan power circuit on the graphic card, or worse damaging the card itself.

  • Original Strix fan: 12V - 0.55A per fan.
  • Noctua NF-A8:      12V - 0.08A per fan.

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  • Proceed to replace the thermal paste and put the heat sink back. Remember to connect the fan connector.

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My soldering is good, but I did a bad job with the electrical tape, but then nobody will see this horrible mess when it's in use though. The photo also shows you how the PWM cables match in color.


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And this is how the card look after the whole process. Pretty decent looking, I love that Noctua colour!


PERFORMANCE testing

BEFORE MODDING

  • Max temperature during gaming load: 75C.
  • Max GPU fan PWM: 60%

AFTER MODDING

  • Max temperature during gaming load: 80C.
  • Max GPU fan PWM: 90%

Yes you read that right, the temperature increases after swapping out the fans, but I didn't regret my decision. The fact that the card become so much quieter even at 100% full fan speed is so much more important than the 5C increase. Furthermore, the card boost frequency doesn't decrease during load. However, given the PWM at which the Noctua fans are running at, you won't be able to overclock the card much.

When looking back at it, 2x 120mm fans would instead improve thermal performance which would be similar to Linus's findings. However, it would be difficult to find mounting places for the 2 bigger fans.


Conclusion

To me it was worth it to replace the OEM fans on the card.

With that said, I strongly recommend bigger fan to fully utilise the power of your graphic card.