Quote from: Its About Sharing on September 23, 2013, 05:37:24 PM

Quote from: flemeister on September 23, 2013, 02:55:44 PM

Quote from: Its About Sharing on September 23, 2013, 01:18:26 PM

Barntech/Guys&Gals

Does anyone have a suggestion on a fan to use to cool 4 boards on the backplane? (Dimensions? Brand? type? Etc?)
Like a lot of you I will be overclocking the boards and would like to add a fan to them. Would rather have the fan before the unit arrives.

So, looking for a relatively silent fan (Miners are in home) to go with my yet to be purchased silent Power Supply. Grin

Thanks,
IAS

Not sure if it would provide enough airflow for these Bitfury chips, but I'll be trying some Nexus Real Silent 120mm fans. It's cheap, it has good static pressure considering it's moderate speed of 1100RPM, and it's pretty quiet even at full speed. SPCR has been using it as their reference 120mm fan for at least seven years now, for good reason.

http://www.silentpcreview.com/article695-page2.html#nexus

Scythe Gentle Typhoon would be another good option.

Thanks for the information. I looked up that Scythe and it looks perfect (and potentially quiet).
Questions:
- How many would one need for 4 boards with backplane? The fan is roughly 5" X 5" and not sure how big the 4 boards would be (from the side, where I think I'd put the fan to blow across boards all at once).
(edit - I found Barntech mentioned this a few pages back "102mm x102mm for the 8 board (will fit in a hdd bay)" Not sure on the spacing in between the 4 boards, but one fan might cut it, thoughts?)
- Which model (rpm's) - I see 850, 1450 and 1850. I heard you can control the speed on them with a voltage regulator but how do we do that with just a power supply? Maybe from the Raspberry pi?
- Suggestions on how to mount them near the boards?

BTW - While we are sort of on the topic of power supplies as well, a 4 card setup is only going to use 64 watts (if ran at 2 watts per chip) and maybe up to 80 watts (if ran at 2.5 watts, near max, per chip). I'm not even sure if getting a 350-400 watt power supply is too big. Most power supplies talk about efficiency at 20% (minimally). Well, a 400 watt ps would be running at 90 watts there. Can they even run this low? I don't see any 200 watt or so power supplies like I do the 350-400 watters. I like the new corsair rm450. Would run silently at this level, if it can run this low.

Thanks again for the ideas. Hopefully this helps others as well.

IAS

I have a question...these units will use a 4 pin molex,the ones for old IDE hardrives/cd roms,will they need the 5 volt circuit Huh

I want to make cables myself & would like to use PCIExpress 6 pin as a base connection for the 12 volt power draw & then add up to maybe 5-6,4pin molex connections.If they do need the 5 volt then I'll just have use the 4pin molex cable & determine the max wattage on that line as to how many units I can power with that line.Most cables on the PSU have 4-6,4pin connectors from the "factory" on each cable.

Look under section,Disk drive connector (Molex 8981 Series Power Connector):
http://en.wikipedia.org/wiki/Molex_connector