I could use a sanity check on a cooling situation. It doesn’t seem right or possible. Sorry for the long post.

CPU: AMD 9700X MB: Asus TUF Gaming B650E Wifi RAM: 4x16GB T-Force CL30 Case: Antec P182 (Giant quiet gaming case from 2007)

The system has been together for about 5 months. When I got the components, I picked up a $30 CAD generic cooler:

“iCan 6-Heatpipe CPU Cooler | 2*120mm PWM Fans with Rainbow Color | TDP - 265W | Fan Speed upto 1800RPM | Fan Noise - 31DBA”

It all ran OK, was quiet but not silent. Only has fan noise when working hard. In other words: Great.

I’m doing a bunch of ffmpeg/x265 transcode benchmarking. With the iCan cooler, it would thermal throttle (75C throttle, 76C measured) at 5350MHz. It would bounce between about 5200 and 5450.

Anyway, a buddy told me the Noctua D15 is the best air cooler going. I did some reading. He seems to be right. It is a highly regarded cooler.

The D15 fits into the system fine but only one of the 140MM fans will fit. The 140mm fan won’t fit in the back, due to the VRMs. The 140mm fan won’t fit in the front, due to RAM. So, the D15 has a 140mm stock fan and a 120mm screamer (140CFM). That’s a lot of air.

It doesn’t cool nearly as well. Not even close. I’ve bumped up the thermal throttle to 80C (where it sits 100% of the time while transcoding). Fans are set to 100%, all the time. It barely makes 5GHz with the D15. Average is about 4900MHz.

I put the iCan cooler back on and it went back to almost boost clock frequency.

The thermal paste is very well done. I was super careful between cooler changes and I clean the old stuff with alcohol before applying fresh and mounting another cooler.

Why does the smaller cooler with a far worse machined CPU contact area cool better than the gigantic D15?

I will say, when using QFan and the iCan cooler, the fans ramp in about 2 seconds after launching ffmpeg. QFan with the D15, it takes about 4~5 seconds for the fans to fully ramp. The D15 has a substantially heavier CPU block and this does seem to add considerable inertia (which is nice).

Any thoughts?

  • CameronDev@programming.dev
    7·
    21 hours ago

    The d15 is normally a fantastic cooler, so something isnt right. Is it brand new? Long shot, but are there any cracks on the heatpipes? If the liquid has leaked out it won’t work well?

    I have one with only a single fan in the middle, and it worked fine, so unless you put the two fans pointing air at themselves, its not the fans.

    I’d return it for a replacement, it sounds like you’ve tried all the reasonable steps.