BFL Single air flow?

[rupy]

I used BTC, but I used mined BTC so "no problem". I bought FPGA, so I'm still ROI all-in-all, even after ordering BFL. Now I'm just trying to cool these silently so they can heat my house, going noctua today, fingers crossed!

Edit: Noctua 92mm on top blowing down and usb fan pushing sideways (only required because aluminium heatsinks are directional), 79 degrees, 57GH. And silent enough to not go insane while sitting next to it.



Damn BFL for replacing the heatpipes with aluminium heatsinks though (and not even replying on queries about buying heatpipes), could have made it completely silent with those!

I'm going to start project "turn heatsinks 90 degrees". Need to make new screwholes...

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[rupy]

Ok, an update, you need to replace the thermal pad with thermal grease... the chips are completely leveled, at least on my machine, 10 degrees difference!!!



Then for silent cooling it's this side that needs it. I chooked the sideways fan so it doesn't blow on the top fans, you could try with a smaller fan that doesn't reach over the top too. Edit: definetly go for 92mm fan for the side fan.



The little black thing on the right ledge is a spider that likes the miner. It lives next to it!

It's not sleep quiet, but it's almost work quiet, not in the same room, but at least it keeps the neighbors from complaining.

Too bad BFL "ran out" of heatpipes!

EDIT: The position of the side fan is dangereous, I suspect it blows directly at the temperature sensor therefore tricking the single it is cooler than it actually is. I burned 1 chip for good and 3 more that needs cooling before booting to work! Damn BFL for not delivering heatpipes so we could cool these quietly!!!

The chips are all back, seems the firmware is shutting things down if they get too hot; even across reboots!?

[rupy]

Received my RMA Single, something has changed, lots of components are different and it runs MUCH cooler, 62C with thermal pads!! Only 55GH but definetly an improvement. Running the BFL PSU for 4 days until I move the Single to my house, boy that PSU is some nasty peice of hardware, hope it will last 4 days, doubt it.

Edit: cracked the PSU open after 10 minutes of soul scorching noise. Cooling it with another silent fan instead.

[rupy]

Ok, last update I hope (is anyone even reading this crap?) so I now choke the two top fans (with resistors to reduce noise) and keep the side fan full speed. It seems the side fan position is the secret sauce to cooling these, it induces an airflow of fresh air between the heatsinks through the slim gap between the sinks and the top fans. Getting taller risers or cutting the sinks a little (need to keep pressure on the whole side of the PCB to cool other stuff) would maybe perform miracles. That did NOT work, hotter and more turbulent... Anyhow even more silent now and only 1 degree warmer!

[ewibit]

I get always

Code:

 hex2bin scan failed

with my LS and cgminer 3.8.x
is this perhaps an issue with temperature?
I have to unplug the device and in a few minutes replug and with luck it is working again (a little time...)
TIA

[foobar31]

Just my 2 cents if people are still using this device and trying to mod it.

I tried to replace the default fans by others (which were not good enough in terms of pressure...) but it makes me discover something after re-mounting the default ones...
For me it appears that the flow direction has a high importance, you'll get better result if it goes from right to left when looking at the SC from the rear (where the power/usb connectors are).

With the default fans and an open box : 64°C +/- 1°C
In the wrong direction : 70°C +/- 2°C

Cheers

[Gator-hex]

Fans should always blow down into the heatsink, not only do they run cooler this way around they also keep the other components cool on the board cool too. This is especially important for VRMs/power modules.

Bigger fans = less noise. The design of the blades doesn't matter as much as a lower rotational speed for getting noise down. Getting extra number of blades in the fan improves CFM (airflow) for the same rotation speed.

If people want low noise miners I recommend the Bitfury chip stuff as they don't get very hot.
My Hex16B are running 92mm Arctic F9 (9 blade) 1800RPM 0.4 SONE 43CFM fans and they're quiet enough to be in the same room I watch TV.