The Tower of Prisma
Solved a lot cooling issues this way and freed up some rack real estate in the process.
Mounted this way the boards are running about 60F cooler.
On to OC'ing them.
Sorry about the blur, was standing on a chair and I'm an old fart.
You said in this configuration they are running 60F cooler? What were your numbers before and after? My setup looks very similar with the box fan under it. Plus I have two fans on each prisma, the one stock drawing air in and the one philipma1957 suggested to pull air
http://www.amazon.com/gp/product/B00A460TK6/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1 Those Silverstone Tek 140mm x 38mm Fans are really quite even in power mode. I have them all hooked up to a fan controller that GrapeApe recommended
http://www.amazon.com/gp/product/B00DN3IT7M/ref=oh_aui_detailpage_o02_s01?ie=UTF8&psc=1 I have them all running at full power, the stock fans are loud, like a hairdryer as some people say. But if that setup you have going is actually running 60F cooler and the stock fans are cycling you just maybe on to something. With my setup minera is reporting 85-86F running @ 240mhz. Im just curious what your numbers were before and after. Also im not sure where minera is getting the temp numbers from, does anyone know? I saw a post on this thread where someone said it could be the RPI temp, so I don't have a clue. Now I have to go give the leaning tower of prismas a try, will report back. Also im a little worried of them tipping/falling over, so maybe secure them somehow from the top.
Without getting all esoteric, horizontal the back bracket was typically 176F @ stock clock (240) and unit was sporadically rebooting.
Mounted vertically as in the photo with the box fan below on high (~2000-2500 CFM) the back bracket is is a chilly 110F-112F.
There has always been a 50F delta T between the front chips and the back chips. And that Delta remains in this config.
Ambient air temp oscillates between 70F and 80F due to the powered roof vents cycling. And air is drawn in from the outside (4F-20F air) through a screen door.
I'm almost 100% sure that the temp reported on the dashboard is the temp near one of the vertical connectors on the Pi.
We used some beefy zip ties to hold it to the wire mesh.
The first time the fan cycled it scared the shit outta' me cuz' it got real quiet and I was sure I blew sumpin' up.
Yes they are louder than hair dryers and they are the loudest miner in the DC.
A little birdy whispered in my ear and told me that 70% of the heat dissipation in a Prisma is through the heat sinks the other 30% is out the component side of the board.
Be back l8r with pics.