7970 Fan Mod

I have an AMD 7970 Vapor-X, and due to a fans being too loud and one of them turning on only after pushed to over 75% RPM, i would like to make a fan mod.

Idea 1) I would remove the plastic chassis, and add two currently unused 120mm case fans, which would be suspended from the GPU using zipties, blowing cool air towards GPU. Some guy actually already did it.. I would probably have to buy a fan controller to connect and control those fans.

Idea 2) I would buy one 140mm 4pin PWM Fan and do the same as above, except i would connect it to the GPU, which would allow regulating it depending on GPU temperature. I would use this fan on my case in the future, after eventually buying another GPU. I could also have another 120mm 3 pin fan at a constant RPM alongside 140mm fan with scaled RPM.

My biggest concern is how would a 140mm PWM fan scale with the GPU software. Would it be too weak, or too loud? I would appreciate any input on this ghetto idea from the tech savvy. Please note that silence is more important than performance to me, and if i spend any money on this it would prefferably be on components i could also use in the future.

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Originally Posted by AOD_RedBag

I have an AMD 7970 Vapor-X, and due to a fans being too loud and one of them turning on only after pushed to over 75% RPM, i would like to make a fan mod.

Idea 1) I would remove the plastic chassis, and add two currently unused 120mm case fans, which would be suspended from the GPU using zipties, blowing cool air towards GPU. Some guy actually already did it.. I would probably have to buy a fan controller to connect and control those fans.

Idea 2) I would buy one 140mm 4pin PWM Fan and do the same as above, except i would connect it to the GPU, which would allow regulating it depending on GPU temperature. I would use this fan on my case in the future, after eventually buying another GPU. I could also have another 120mm 3 pin fan at a constant RPM alongside 140mm fan with scaled RPM.

My biggest concern is how would a 140mm PWM fan scale with the GPU software. Would it be too weak, or too loud? I would appreciate any input on this ghetto idea from the tech savvy. Please note that silence is more important than performance to me, and if i spend any money on this it would prefferably be on components i could also use in the future.

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Most GPU Fans use a 2Pin Female fan header on the edge or outer area of the PCB, In order to connect the 120's to the actual GPU's 2Pin headers you'd need to either 1) Buy an adapter, or 2) Buy x2 fans w/ a 2Pin Male fan header(Hard to find, especially in larger sizes). Thats a great GPU, And cooler, I wouldn't go messing with it just to drown it out a few Decibel's- Its a Tahiti based GPU so its naturally going to run hot.

It's my understanding that the Vapor-X series has some of the best heat dissipation for air cooling.
Noise is the the trade off for lower temps. (generally)
In the future I suggest reading reviews that include temp/noise levels.

Example review > ***NOT FOR 7970
290X Vapor-X Review

-NOT RECOMMENDED-
For the fans, you can just plug them into a chassis fan slot and they will run just fine. Make sure you get low noise level fans though!
I believe the direction of airflow should be towards the gpu (and out the back of the card)
This is a terrible idea

Quote:

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Originally Posted by AOD_warlon

It's my understanding that the Vapor-X series has some of the best heat dissipation for air cooling.
Noise is the the trade off for lower temps. (generally)
In the future I suggest reading reviews that include temp/noise levels.

Example review > ***NOT FOR 7970
290X Vapor-X Review

-NOT RECOMMENDED-
For the fans, you can just plug them into a chassis fan slot and they will run just fine. Make sure you get low noise level fans though!
I believe the direction of airflow should be towards the gpu (and out the back of the card)
This is a terrible idea

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Its not a terrible idea, and as I pointed out, the VaporX Coolers are the best(if not, of) aftermarket cooling solutions for Sapphire's AMD Cards; Again, the Tahiti/Tahiti XT GPU's run very HOT, so naturally the fans are going to run at a higher RPM/Speed.
And Like I said, If you want it to look remotely "ok", your going to want to use the Cards 2Pin fan Headers on the board, rather than snaking out 3/4Pin Fan cable's to your board or Fan controller-

After some more research, i found this very helpful thread. The results this person got are amazing, it looks and performs great, and he even lists exactly what do you need.

However, i would ideally like to only spend on fans that i could re-use later (so 140mm and no adaptors).

So the question for physicists: how do two 90mm (15mm thick) fans spinning at about 3200 RPM (about 75% speed, which is the fastest they get for me) compare in moving the air to two 140mm (25mm thick) fans spinning at about 1000 RPM and are rated to move air at about 100 m3/h (i'm looking at Noctua NF-A14 variants). With a side note that a small part of the 140mm ones would extend beyond the GPU surface.

I have decided to go ahead with this mod:

1) Bought a VGA to PWM adapter and two Noctua NF - A14 fans.
2) Removed the heatsink and the plastic chassis.
3) Removed stock thermal paste and replaced it with new one.
4) Placed the heatsink back to the card.
5) Placed new fans on the heatsink.
6) Tied fans to each other with zipties.
7) Tied the two fans to the card with wire (did not have zipties narrow enough)
8) Placed the card back to motherboard.

Results: The fans hang from the card somewhat loosely, because i should have used zipties instead of wire. They are much more silent than the stock ones. One of the stock fans rattled and would not spin up until temps hit 70 degrees, which meant i would suddenly hear jet engines from my computer. New fans are not audiable even at full GPU load. Temps now hit 60 degrees and don't go beyond. The fans spin up to 900 RPM (unlike upwards of 3000 with stock). No adjustments of fan curve required.

I could not have hoped for better results, silent gaming here i come!

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Quote:

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Originally Posted by AOD_RedBag

I have decided to go ahead with this mod:

1) Bought a VGA to PWM adapter and two Noctua NF - A14 fans.
2) Removed the heatsink and the plastic chassis.
3) Removed stock thermal paste and replaced it with new one.
4) Placed the heatsink back to the card.
5) Placed new fans on the heatsink.
6) Tied fans to each other with zipties.
7) Tied the two fans to the card with wire (did not have zipties narrow enough)
8) Placed the card back to motherboard.

Results: The fans hang from the card somewhat loosely, because i should have used zipties instead of wire. They are much more silent than the stock ones. One of the stock fans rattled and would not spin up until temps hit 70 degrees, which meant i would suddenly hear jet engines from my computer. New fans are not audiable even at full GPU load. Temps now hit 60 degrees and don't go beyond. The fans spin up to 900 RPM (unlike upwards of 3000 with stock). No adjustments of fan curve required.

I could not have hoped for better results, silent gaming here i come!

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Not a bad looking mod at all; What PWM/MOSFET Heatsinks did you buy to replace where the Thermal pads where?
**I hate the poop-brown color of the Noctua fans, but they are some of the best fans on the market, I just wish they'd give them a REAL color change: Their Industrial PPC, And Redux fans STILL look ugly as hell, the PPC's still have a dark brown on their silicon corner's, and the Redux's shade of gray is terrible; They know how to engineer excellent fans, but who ever comes up w/ the color(s) for their fans is either stubborn as all get out or very...very..Colorblind.

I'd buy 6 of them if they made a smoke-black or Just all stealthed-black fans w/ the Silicon Corners.

** Can you post a higher-res/better quality photo(s) of the card installed; Its really choppy :(

@Grady666, i haven't heard of the PWM/MOSFET Heatsinks before, i didn't replace the thermal pads.

I actually like the color, it would look good if everything else was black. It maches the piano in my room (or it would, if i had one). I use a closed case anyway.

As for the pics, i have horrible cable managment, so higher res pic would actually look uglier.

Quote:

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Originally Posted by AOD_RedBag

@Grady666, i haven't heard of the PWM/MOSFET Heatsinks before, i didn't replace the thermal pads.

I actually like the color, it would look good if everything else was black. It maches the piano in my room (or it would, if i had one). I use a closed case anyway.

As for the pics, i have horrible cable managment, so higher res pic would actually look uglier.

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Here is a MS Paint (Lol) Diagram I made highlighting the MOSFET's/SMT Capactiors/& Inductors(This as well as a Digital Pulse-width Modulation IC is what makes up the Voltage/Current regulation Circuit(s) for the GPU)

**Might need to click on the image to expand it

The VRAM/Memory should have (each of them) their own Individual Heatsinks(Most come with thermal-adhesive tape so you just peel and place) and the MOSFET/SMT Cap's and Incutor(s) Is more of a large group of IC's, often there are individual heatsinks(varying in size and surface-are/shape) for each MOSFET and sometimes their are larger Flat/Horizontal heatsinks that are placed over the entire Voltage/Current Regulation circuit.

** You should ALWAYS replace the thermal-pads if the card is 4-6+ Months old when doing any type of custom cooling solution or a Universal GPU Water-block on your card

Without these, your card will heat up considerably, even if it runs fine without them its a good idea to buy some of these and place them on there-

Also to answer your previous question about how a larger 140mm fan moves air at lower RPM's than a 120/80mm fan is because the fan(s) blades are larger and more dense so they dont have to rotate as fast to achieve the same amount of air flow(CFM;Cubic Feet/Min)

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