Cutting my passive heatsink to fit (?)

[eiselx86]

Hey guys!

I got the Arctic Alpine 11 Passive heatsink pared with i3 2120t 35w. It's about 5mm too high and I really want passive cooling. Can I trim/cut the fins?

My thinking is by removing ~ 5% of it's total mass shouldn't affect it's thermal dissipation that bad. The fins are only made of aluminium with no heatpipes. Thermal dynamics isn't my expertise so I might be totally wrong.
Any opinions?

The case is a modded 14L receiver with 60mm intake plus 40mm and 80mm exhaust from noctua. The cpu have a vent right above it. Imgur: https://i.imgur.com/TZ0cDCb.jpg

Cheers

 

[zovc]

You definitely can work the heatsink. If it's not got any heat pipes, there isn't all that much risk involved.

The only concern I would have is: this is a "passive cooler", but it definitely looks to me like it's designed to be used in a case with air circulation.

But for whatever it's worth, Linus' Tech Tips has done DIY heatsinks before, and if they can hand-make a thing that keeps a CPU from blowing up... this factory made unit, minus a little bit of material, should do just fine.

 

[eiselx86]

You definitely can work the heatsink. If it's not got any heat pipes, there isn't all that much risk involved.

The only concern I would have is: this is a "passive cooler", but it definitely looks to me like it's designed to be used in a case with air circulation.

But for whatever it's worth, Linus' Tech Tips has done DIY heatsinks before, and if they can hand-make a thing that keeps a CPU from blowing up... this factory made unit, minus a little bit of material, should do just fine.

Tried cutting one of the fins and it's only aluminium. There are multiple versions of the same heatsink but with differrent fans. Wish I had some server grade stuff.

Yeah I thought it shouldn't decrease the performance with more than 10-20%. But googling only showed examples of heatpipes so I felt unsure.

Picture with airflow design:
Thanks for the input! Gonna cut the rest after work and post my results.

 

[eiselx86]

After a lot of cutting and sanding the result is pretty good. Temps in bios were 29°C and my temp reader was hovering around 27-31°C. Had the system running for 1-hour open bench test. Got no boot drive atm so can't stress test it, unfortunately.

 

[BaK]

I would have used a file with such a soft metal as aluminium, but it looks like the dremel did the job!
Nice retro case, good idea to pair it with a NATi's kit!

 

[eiselx86]

I would have used a file with such a soft metal as aluminum, but it looks like the Dremel did the job!
Nice retro case, good idea to pair it with a NATi's kit!

Yeah I actually tried to use it but the fins is very flexible/soft. Didn't want to risk crackling it. Smoothed out the edges with a grinding machine at work. Dremels aren't precision tools exactly After running stress tests and benchmarks it surprises me how good it handled the heat. On top of that, I accidentally had installed a 65w tdp chip instead of the 2120t. Max temp was 65-70c at full load after 1-2 hours.
NATi's kit is simply amazing!