Quote from: MrTeal on January 13, 2015, 06:11:25 PM

Quote from: Biodom on January 13, 2015, 03:30:08 PM

Quote from: BITMAIN_Kiddy on January 13, 2015, 10:09:44 AM

Quote from: Biodom on January 13, 2015, 04:26:40 AM

Stock fan produces ~69db, which is not typically tolerable in the house (apart from basement, attic, garage, shed)
Fan play to have as much hash as possible while maintaing low dB:
~30C ambient
1. Noctua 3000 PWM ($24.5, 110CFM, up to 3000rpm, just 41dB) in push position: ~59-61C at 325mhz, 1070Gh; less stable at 350mhz.
2. Scythe Ultra KAZE ($15.3, 130CFM, 3000rpm, 46dB) in push position via molex adapter-worse than Noctua, temp rising close to 65C at 325mhz, discontinued. Strange result as this fan has nominally higher CFM than Noctua.
3. Noctua in push, Scythe in pull (connected to molex through included adapter), up to 337.5 mhz is stable (1100 Gh).

Conclusion: adding Scythe ($15) in pull might be not worth it as it adds just ~30gh.
I simply taped Scythe to exhaust in pull orientation because could not find proper screws yet.

Question: anybody knows what are the characteristics/dimensions of the machine screws Bitmain is using for fans? They seem to be in between 3 and 4mmX42mm, but I wasn't able to find such screws easily. They are not 3X40mm for sure. Anybody have a link?

Hi, the screw we're using for fans is PM4*42.

Thanks, but it is a little cryptic. What is PM? The search for "PM4*42" or "PM4*42 screws" returns nothing relevant.
can you point to the source that is readily available in the United States? Amazon, ebay, grainger, english version of alibaba (less optimal because of long delivery time), etc.

Philips head (or maybe pan?), M4 thread, 42mm long.

Thanks, guys.

Quote from: ryanjf on January 13, 2015, 06:12:35 PM

In the US they are M4-.70 x 40 without the fan grille and M4-.70 x 45 with the fan grille. Mine are Hillman brand, got them at Lowe's.