Topic: Klondike - 16 chip ASIC Open Source Board - Preliminary - page 93. (Read 435369 times)

I'm not sure why the PCIe spec says only use 2 pins each for power. Both the Corsair PSU and AMD Radeon adapter cables I have both use all 3 on both sides. So I guess there must be some optional use or something.

I would recommend using 2 wires at least even if jumped between pins on the wires. I'm more concerned with all the current flowing through 1 pin on the PCB joint to copper. It's likely within ratings but will cause more heat than spreading it over 2 or 3 pins.

Yes, you want turbulent flow for mixing near the wall. You want Reynolds number to be above 4000, at least close. But assuming all variables are held constant, larger pipe diameters produce larger Reynolds numbers. Re = (rho*V*Dh)/mu. However, if your larger pipe diameter reduces velocity then you will not see a Re increase.

for efficient cooling with water better use small pipes to achieve a turbulent flow (see Reynolds number).
german users find all neede info in this book:
VDI Wärmeatlas

another aproach is to use heatpipes, perhaps also fanless.

If you want to do some kind of custom cooling setup or radiator setup for a fan let me know. I have a machine shop with plenty of tools to make it happen. Be interesting to see the final outcome from this. I also lol'd at the thought of you jumping around! 

Heat treating oven for steels



Industrial grinder with 2 hp 220v motor



Metal lathe



2hp mill weighting in at around 1000 lbs with DRO and power feed

So the water is running through the inside of the "box"? The largest problem with any setup like this is making sure that there is conduction between the chips and aluminum to the water. There will be no convective cooling in this setup (such as blowing air over the chip without any heat-sink). I also wouldn't consider setting something like this up along with a radiator and fan as "easy" unless you already have this stuff around. But I would have to see a design to make sure I understand what you are talking about.

Edit: OK, I've seen a design similar to what you are talking about. So, these current designs are placing heatsinks/aluminum housing on the underside of the board... how is heat being conducted from the thermal pad on the chip, through the board, and to the heatsink/aluminum? If it is just silicon then there may be a conduction/heat-transfer issue. It seems that this QFN design isn't really made for external heat dissipation.

-BKK 

I support this !

lol

thats exactly what i thought when i read his post.

Famous moment in the history of Bitcoin: BKKCoins hopping around his workbench. Makes me think of Archimedes running down the street naked.

Maybe in the history books BKKCoins will have been hopping in the nude.

You remember from avalon-ref "golden nonce=received nonce - 0xC0"?

Congrats on your milestone BKK ! Keep up the great work !

I don't think that would really be a problem.  The PCI-e 6-pin connector has a design specification of 75W, and the pinout is:

Pin 1 - +12V
Pin 2 - N/C
Pin 3 - +12V
Pin 4 - GND
Pin 5 - Sense
Pin 6 - GND

So, looking at the wires actually delivering power you have 37.5W on each +12V / GND pair at the rated PCI-e spec.  On top of that, the connector is actually rated for higher power delivery- more than double the 75W specification.  Assuming you use proper diameter wires and good termination, one pair of power wires will be more than enough.

tl;dr: yes, it would work ok.

(edit) Just noticed you had said pin 5- you would want to use pins 1 and 4, not pin 5.

Quick question; what would happen if I had a PCIe connector and only ran 14 gauge wire to pin 1 (+12v) and pin 5 (ground) and connected that to a K16? Would it work ok or do I need to have 6 wires connected?

What about puting the hole thing in a fishtank and submerge in mineral oil to cool ??

a radiator of course to cool it back

I thought about doing the same thing to the heatsink, making the water snake around before exiting.. I'm not sure about the cooling setup with the fans though, while effective, it causes evaporation, you'd have to refill the water tank daily, not to mention raising the humidity in your house to mold-causing levels.
I would rather park a radiator under my house and one outside and run the water through those.

good job!

congratulations,
very well done,
treat yourself to a cold one......  pssssssstt   

cheers,
kev

I like this idea, its very doable and would be very power efficient. I dont think you would want a basic Aluminium box shape though. Best approach may be to use a heat sink 200 x 200 x 20 minimum with a gap between fins centreline of about 10mm.
Trim each alternate fin by 15mm from its edge and do the same on the opposite side but on staggered fins from those first cut. Weld the end plates and then place a flat rubber mat (2mm thick) 195 x 195 on top of the fins and the closing plate on the top, then seal weld all around. Use a 10mm aluminium nipple for the inlet and outlet which will be on opposite diagonals. The water path would then "snake" backwards and forwards as it travelled laterally from inlet to outlet. The fins are important as they will transfer the heat evenly into the moving water like a conventional tube heat exchanger.

The outlet would be fitted with a rubber hose which transports the water well away from the rig  before it is squirted onto the top of a vertical (fine) corrugated plastic sheeting, as the water runs down, it is cooled rapidly by a few 20 W desk fans blowing cool air onto the corrugated surface. The cool water is collected in a simple plastic reservoir and pumped back up a rubber tube to the inlet via a submersible adjustable aquarium pump. PCB would have to be attached to sinks by double sided adhesive thermal pads and only use Aluminium nipples as any other different metal will cause galvanic corrosion and cause leaks. A low power small aquarium pump of say 20 LPM would do nicely. Flow can be adjusted until the heatsink outlet temperature is low enough.

It is something I might just try  

cheers,
kev

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