Topic: Klondike - 16 chip ASIC Open Source Board - Preliminary - page 146. (Read 435369 times)

How did you solve the precomputation?

Thank You Zefir. I'm awestruck. Really. Will be in touch soon.

I've just pushed up what I believe to be close to final Gerbers. I fixed a number of small things, and added proper paste/mask layers adjusted for thermal pads. I re-checked most of the footprints. I'll be checking it again and hope more expert eyes will scan it. Maybe I can order first boards from this on Monday.

Zefir,

Thank you very much for your support and especially donating to BKK.

And pls do not worry we will (Personally me) destroy our (mine) avalons only we had to
Let us hope that sample chips will be available before that

Best!
PS: I am wandering why none with broken PCB is willing to sell it but it is another story

Tip o' hat to Zefir

+1

Agreed

Dear BkkCoins,

I am watching this thread and your project closely and I stopped by to demonstrate my respect for your work.

When I agreed to fund chips for distribution to DIY folks and supporting Open Source projects, this was exactly what I hoped to enable. Working Open Source does not only mean throwing some documents to GitHub - it also implies you personal openness to listen to your supporters and consider resulting ideas. Having so many contributors actively following you is your ultimate proof that you did everything right.


I would be glad if the 10 BTC I just sent to your address (1BvpJvejSmtWjuDfytZL5HTBUjoXokazp9) could help you to at least cover some expenses on your way to a working prototype. Let me know when you need more. Additionally, I have you on my list for projects to receive a portion of the chip samples (so no need to destroy working Avalons for that, folks).

As my potential contribution to this project, I might be able to win a very experienced and skilled developer to design a custom water-cooling block for Klondike that will also be released as open source. Please PM me as soon as your time allows to provide the relevant technical specs.


Best of Luck,
zefir

This is more complex than that. An approximation would be that the amount of "surface x airflow speed" should be the highest possible. With fins you get more surface with narrow fins but you slow down the airflow. The sweet spot depends on the pressure applied on the fins: the more pressure the faster the airflow even with narrow fins. To get high pressure you need a powerful fan and funnel the airflow so that he can maintain the pressure along the fins.

If you can't maintain good pressure (fan firmly in place on the fins covering most of the surface, or blowing from the side with a funnel directing the airflow into the side and a cover on top of the fins), the usual good spacing is around 3+ millimeters between fins (see low airflow CPU heatsinks).

Last note : if you can't anticipate the flow direction, fins may not perform as well as pins.

Ok I'll check in monday with Alu profile suplier for more suitable raw profile.
I'll prepare a Cad drawing and will post here .
After We decide it'll work I'll send to you the CAD to be added to the project

Also if the fins are narrow then drill the fins to accept a spring and long bolt on that side, a bit wider than bolt. The heat sink should probably not be tightened directly to the board but have springs for pressure, much like CPU heat sinks usually have. I think wider fin spacing is likely better anyway as it will allow better air flow. I'm not an expert on thermals but I suspect that narrow fin spacing are better suited to convection (passive) use.

Ideally there would be a group of holes or non-thru hole dents made at the PCIe power connector location to allow for pin protrusion. I've allowed for an alternate Phoneix SMD power connector but that is not as standard and easy to use a solution as a PCIe connector. So if custom heat sink machining is done it makes sense to include this.

I think what we need is a 90 x 80 mm maybe 1.5 inches height and fins in one direction. Drilled in 4 places to accommodate 4-40 screws.

computer aided design...

I am neither savvy nor skilled in CAD. Hope someone out there will with the spare time can do this. A stencil design for soldering be nice as well for the land area and the chip itself. That way we can try different companies all over the world possibly find a cheaper metal stencil that we can all order directly. The chip stencil could be bulk ordered now as it won't change at all.

Please share with us idiots who aren't savvy with cad...

People following this thread with C.A.D. skills can do several heat sink designs and do the heat dissipation calculations for them?
Whether they are passive and with fans as well could be helpful right?

That way we could come up with the ideal profiles for the K16 / K64's and solutions for stacking.

I have been scouring AliExpress for VGA/GPU heat sinks with fans, older CPU heat sinks with fans and water blocks for CPU's and GPU's that might work with the 100*100mm profile available. There are definitely a lot of after market or in stock items that could be sitting on shelves right now that could be bought and fit this design or retrofitted given some good ideas.

Tru unless we do have time for a month shipment of the heat sinks. For a big order it will not matter

Think people need to do heat sinks in local context. Larger orders shipped world wide going to get expensive for weight right? I am looking in Indonesia for a supplier for my boards. Might be smart for those with larger orders of boards to simply put heat sinks on after getting them.

Also there will be a variety of possible heat sink even water block options you may even try as a DIY or retro fit solution. What I am doing myself is to track down the following:

1. Heat Sink suppliers in my region.
2. PCB fabricators / assembly in my area.
3. PSU suppliers in my city.
4. Rack mount server case suppliers in my city.

If you are just making a few boards then you can also look at options for re-flowing the chips yourself in terms of finding the following:

5. Soldering / Reflow stations (Heat Gun / Solder Iron Combo).
6. Re-flow oven.
7. Stencils for the QFN 48 that would match the specification for the chip.

If you are not the DIY type then I suspect you need to check with those of us who are going to assemble full working boards and get in line or wait for us to complete our work.

Personally I am simply going to park and watch BKKcoins do his stuff. He will go through all of this carefully and when he is ready he will release this project to the wind and we will all be ready and I suspect just waiting for chips to REFLOW to Klondike boards from K1 to K64. What we all can be doing right now is our research and lining up our suppliers / fabrication etc or DIY getting all the required equipment you may need to do this.

Nothing wrong with getting your ducks in a row right now but really we have to sit back and wait patiently for the next 2 weeks as BKKCoins has some fun solving this puzzle he has created. I wish him the best of luck... no pressure right?  

Might be good if those who are starting up assembly have their threads and speculate there on heat sinks, psu's etc that way you can localize your builds and get suppliers that are well known and respected. I am really doing a lot of that right now and it isn't easy to find the right people and I am hopeful I can find the right people and companies well before BKKCoins has finished testing a prototype and shown us some hash rates. We are a long long way off really but that is great because everyone here especially those who will want to build Klondikes can get everything in place ready for us to kick start this bitch into action as soon as BKKcoins gives us the ok.

Thanks, is this the repository you mean?  https://github.com/BitSyncom/avalon-ref

Concerning modules almost all info is already on their github except Power PCB BOM
You can check it.

I thought the chips were roughly 2.5watts each, so 16 x 2.5 would be 40watts rather than the 32watts in the OP?


Has anyone heard anymore from Avalon about the open source details of their modules that were supposed to be released in May? It's just we are over half way though May already.

Yes, of course , I'll have to check for availble profile. Original is cut/drilled in standard profile too.

On topic
here is sample drawing with a profile that we source for our customer


Uploaded with ImageShack.us

Could always create a rigid backplate like some motherboards and big heatsinks use?

And since the heatsink will be clamped flat/flush to one side of the PCB will flexing be an issue anyway?

Hear,hear!!!!!!!! I am watching this endeavor with GREAT interest & gathering coinage to take part in "The GREAT DIY ASIC RACE".

Thanks to all involved for opening this to the masses 

I have much more to say.....but am keeping quiet