Modding GPU coolers into CPU coolers

[aquelito]

Our discussions with @Tossy gave me the motivation to finish this long overdue project :
to use a Thermalright Shaman I bought for 15€ to cool an Intel CPU.

After two hours of measuring, drilling and cutting some exsting aluminium and copper pieces, I obtained a working 40 mm high top-down LGA 115X cooler !

I had to orient the heatsink this way to avoid some capacitors around the socket.
Total height without fans is 52 mm from the bottom case panel to the top of the cooler.

With a 15 mm 140mm fan, total height is 70 mm.
With a 12 mm 120mm fan, total height would be 64 mm !

Otherwise, by just making a new plate, I'll be able to rotate the cooler by 90° and stay within the 170 x 170 footprint of the mobo !!

Please note that I used a thin Mini-ITX board as the clearance under the cooler is pretty low.
On mini-ITX boards, you will need VLP dimms most likely and a 24-Pin extension for your PicoPSU.




It looks badass and it works great on a G4560 !

Some temps after 45 min of Prime95 on both cores (ambiant temp is 22°c) :

- With a Prolimatech slim 140 mm fan @800RPM, temprature stabilises around 45°.

- Run fanless, temperature stabilises around 75°.

 

[Curiosity]

Would you reckon there;s any chance of fitting a fan UNDER there?
I'm thinking it's a bit tight but I don't have one in hand to check.

 

[aquelito]

I tried but there is not enough clearance :/

 

[Tossy]

Interesting results! I really like the small footprint. Though the passive cooling temperatures are not as good as I hoped. Looking at how high they got with a 54W TDP CPU, I doubt I could cool a Ryzen 2400G with this cooler or another GPU cooler under load passively. Admittedly prime is a real torture and unrealistic in normal situations.

The idle/multimedia temperatures are fine I expect?

 

[aquelito]

Idle temps are fine at 35°. Multimedia scenario is not an issue as well.

Yes this little experiment corroborates our first intuitions : this cooler is just not large enough to passively cool anything more than a 35W Skylake CPU.
Even under a more realistic scenario than Prime, temps could stack up pretty quick inside a small case.

If you were to try an other heatsink, it could be the Accelero s3 though : wider-spaced fins make for a better passive cooler.

However, results with a 140 mm fan are great : under Prime95, temperatures did not go above 45°.
If you are willing to use a slow fan, it could work out.

For me, the main issue here is the motherboard compatibility : clearance under the heatsink is a mere 24 mm from the motherboard PCB at lowest point.

I will try to improve the mounting system first, and see if I can improve tempratures.

 

[aquelito]

With that updated mounting plate design, I should be able to mount the heatsink in whatever position I want.
Will add it to my next laser cutting order.

 

[Tossy]

Clearance is indeed low. I don't like the design of the accelero s3 and would prefer the raijintek morpheus II. But the clearance still seems a problem.
I wouldn't mind bending the cooler a bit or shorten some of the fins to improve the compatibility. The question remains: Is it worth it? If I need to use a fan anyways, a L12S or D9L will do a perfect near silent job. Only the height would differ.

 

[aquelito]

With a slim 120/140 mm, performance get pretty interesting.

The Shaman is only 38 mm high, while the L12S is 70 mm high.

This is a huge difference : you could design a 200 x 200 x 80 mm case.


With VLP dimms you may actually pull it off !!

 

[cleveland]

With VLP dimms you may actually pull it off !!

And don't forget the 24p right angle adapter!

 

[aquelito]

No problem with a 24-pin cable

 

[Tossy]

I will try such a build when autumn arrives, but will make room for normal DIMMs. The 2400G is too dependent on fast RAM (>3000mHz) for good performance. The VLPs I can find are all low mHz and low CL, they won't overclock well I assume.

When the time comes I will post a build log here.

How do you fasten the screws for optimal contact pressure to the IHS? You don't use spring-screws I see.

 

[aquelito]

How do you fasten the screws for optimal contact pressure to the IHS? You don't use spring-screws I see.

First I place the cooler over the IHS and measure the distance between the mounting plate and the motherboard PCB.
Then I screw 4 standoffs of the exact length to the mounting plate to be sure that the cooler will be perfectly parallel to the IHS.

Then I flip back the motherboard and screw it to the 4 standoffs.

Very much like you would be doing for a GPU.

 

[cleveland]

No problem with a 24-pin cable

It looked like a bad case of interaction between the heatsink and 24pin location on mobo, based solely on the pic you posted earlier.

Edit: this one, right here:

 

[Valantar]

This is really nice. I'm working on making a CPU cooler (for a future APU build) out of one of my old Accelero S1s myself, although as discussed above, RAM and 24-pin clearance needs careful consideration. I'd especially like to fit a plug-in DC-DC PSU, but that seems pretty much impossible. I'll have to work around that, obviously.
Also, (dependent on socket placement, but still unavoidably due to the size of the heatsink) I'll need to make a custom case to fit it, as it'll overhang the sides of the motherboard too much to manage a brickless build feasible otherwise. Still, I'm hoping the wide fin spacing will let me run it passive (-ish) at idle with a Noctua 140mm blowing into it when I want to push it.

Also, I'm very impressed by the quality of your mounting solution. Nice work. Where do you get your laser cutting done?

 

[aquelito]

Thanks @Valantar !

Besides the clearance issues, the Accelero S1 copper base is much smaller than the one of the Shaman. It measures around 32 x 32.
You'll have to cut a copper block to cover the whole CPU IHS.
Depending on its thickness, this copper block might also solve your clerance issue.

Hereafter the accurate dimensions of the Accelero. You can import this PDF into Rhino or AutoCAD to scale it to the right dimensions.

https://www.arctic.ac/eu_en/downloads/dl/file/id/421/accelero_s1_plus_height_restriction_drawing.pdf

 

[Valantar]

Thanks @Valantar !

Besides the clearance issues, the Accelero S1 copper base is much smaller than the one of the Shaman. It measures around 32 x 32.
You'll have to cut a copper block to cover the whole CPU IHS.
Depending on its thickness, this copper block might also solve your clerance issue.

Hereafter the accurate dimensions of the Accelero. You can import this PDF into Rhino or AutoCAD to scale it to the right dimensions.

https://www.arctic.ac/eu_en/downloads/dl/file/id/421/accelero_s1_plus_height_restriction_drawing.pdf

Thanks for those, I didn't know technical drawings like that were publicly available at all

As for the base size, I actually measured mine to just above 30mm in each direction (maybe they enlarged it marginally for the Plus?), but I'm hoping that will be enough without any kind of shim in between it and the IHS - it's big enough to cover an entire Raven Ridge die, after all, and all the heatpipes are concentrated right above it, so the smaller contact area shouldn't be that important (thus any larger area wouldn't help transfer much heat to the heatpipes, after all).

(That's my R5 1600X in the picture)
As for clearance, I've already bent the heatsink enough to clear the TridentZ DIMMs in my desktop (not too difficult, actually), but I'll be aiming for lower-profile RAM for this build, and I'm hoping I can get it a good deal lower than it is now (currently it stands at around 70mm above the motherboard). 20mm lower would make a case for it quite a lot smaller! The issue then is with any plug-in PSU, as most of those look taller than standard-height DIMMs. Depending on the motherboard and 24-pin location, I might go for either a 90-degree adapter or a short extension cable for the 24-pin.

 

[aquelito]

Nice job ! The Accelero is pretty flexible indeed !

If you need, I converted the technicial drawings into a 2D DWG file you can import in Sketchup.

Since you won't have a GPU, you can rely on 12V PicoPSUS which are smaller than Hdplex 19V solution.

 

[CC Ricers]

This may be of interest to you. A vapor chamber heatsink from a 1080 founders edition retrofitted to a 115x socket. It has a protrusion on the underside to accommodate the CPU well, and the heatsink is very nice looking on the motherboard too.

 

[Valantar]

This may be of interest to you. A vapor chamber heatsink from a 1080 founders edition retrofitted to a 115x socket. It has a protrusion on the underside to accommodate the CPU well, and the heatsink is very nice looking on the motherboard too.

That is a pretty brilliant idea. The design isn't ideal for CPU cooling, seeing how the vapor chamber blocks any airflow going through the heatsink (instead forcing it to do a 90-degree turn to go out the sides), but it should be plenty good for anything in a normal wattage range. Also, it'd be near ideal for a thin build with a side-mounted radial fan.

 

[veryrarium]

I also did "a Shaman on a Thin ITX" thing some years ago to fit in ISK-100 and BQ656.
https://www.overclock.net/forum/23860635-post13.html
Back then I had thought of one half of Accelero Twin Turbo 6990 (basically Accelero Mono Plus), Scythe Setsugen 2, GeForce GTX480 and GTX580 stock heatsinks but never embarked on making the mounters for them. In that OCN thread the OP mounted Accelero Mono Plus.