[SOLVED] Airflow making CPU heatsink rattle

[RamboRyza]

Hi all,

I have a Thermaltake Riing Silent Pro 12 CPU cooler. I've swapped the 120mm fan with a Thermaltake 1225AA 2000rpm fan which cools much better (runs at full speed).

But combined with my Noctua NF-A14 case fan directly behind it, even when under no load (I have the Noctua on a curve starting at about 45% which is about 1400rpm), the heatsink rattles and is getting worse. It's a metal on metal sound and I know it's the fins of the heatsink vibrating from the air volume being pushed through it by the CPU fan change.

Question is, will the rattling fins on the heatsink cause air turbulence, etc which will affect cooling? Or can the fins shake all they want as long as the cooler still firmly attached and nothing is actually moving?

I'm running a 5820k on a X99 Deluxe, 4.4 @ 1.19 Vcore, XTU stable. Load temps max 85c under XTU benchmark but want to know if cooler vibration is reducing my OC headroom.

Cheers!

 

[tennis2]

Pretty certain it's impossible to push THAT much air through a tower cooler to make the fins rattle, but it IS thermaltake.....

This is mostly likely fan blades hitting something.

Turn down the TT 1225AA fan to 50% and see if the rattling stops.

 

[RamboRyza]

Like I said, it's metal on metal. Thermaltake, or any other brand I know for that matter, dont make metal fans as far as I know.
Tried turning down the speed of the 1225, even at minimum speed there is still a slight vibration sound.
It is possible, because I know enough about science to know how air turbulence works.
Can anyone who knows about airflow please reply regarding turbulence and its consequences?
Thanks

 

[Phaaze88]

Can you post an image of the interior? Maybe that'll help.
Use postimages.org or imgur.com

 

[tennis2]

It is possible, because I know enough about science to know how air turbulence works.

And I've used/installed enough tower coolers to know that this is HIGHLY unlikely to happen, even at 2000rpm fan (although you're saying it happens at half that also, which is impossible) unless there's a manufacturing defect of the heatsink fins. There's just not enough airflow to cause the comparatively stiff heatsink fins to vibrate.

Fan blades rubbing on stuff can sound metallic also.

Can you remove the fan (and maybe even the cooler) to see if any of the heatsink fins are bent so as to lightly touch each other? Or if any of the fins are dangling loose?

 

[RamboRyza]

Turns out it was the Thermaltake CPU cooler after all.

Replaced it with a NH-D15S and not a sound, all fans still where they were, no other changes.

Put the Thermaltake cooler in my test rig and lo and behold, it rattles like a tin can full of rocks.

Tennis2, I suggest you install MORE crap tower coolers to learn from it. Obviously your knowledge on the subject of paper thin coolers combined with industrial fans is severely lacking!

Thanks guys!