Almost the same result: 7250-24p, same Mechatronics fans in the back (2), same Sunon 6x6x1 fan on top of the ASIC. I wouldn't call it silent, but a very large improvement. Oh, I also cut out the fan grill (or what ever you call the holes over the fan). ASIC 57C, PSU 36C (without much room ventilation).Wanted to post an update on my infinite quest to silence an ICX 7250-48P (I run this thing in a fairly warm closet with bad circulation). Call me obsessive, but I wasn't a fan (no pun intended) of my temps creeping into the low 70s after my previous fan swap. I believe I have come up with the perfect silent solution for this rig.
Replace all 3 rear fans with the Mechatronics MR4020X12B1-RSR fan. They will read just fine in CLI. Then add a Sunon MF60101V3-1000U-A99 fan to the ASIC heat sink (you'll still have around 1/3" to spare in the case, plenty). Wire it in with Fan 3. All the fans are reduced load vs stock so they won't draw too much and the Sunon only has power and ground, so doesn't affect the read on Fan 3.
The switch now runs next-to-dead silent; temperatures on the ASIC dropped ~20 degrees over my previous configuration into the low to mid 50s degrees and the PSU is in the upper 20s which is great. Been running around a week, everything has been perfect. I'm in love.
I tried Sunon in the back before (MB40201VX-000U), and maybe the same absolute noise level as the Mechatronics, but the Sunon had a more annoying sound.
I mounted the ASIC fan with two screws into the ASIC fins (I went through my collection of screws until I found something that worked).