Klondike - 16 chip ASIC Open Source Board - Preliminary

[Sophokles]

I'm following this thread with a lot of excitement, I do alot of hardware developing myself, and I would in future want to order pcb's for soldering and programming myself.
But my thoughts are about the chips. There are tons of group buy, but, how do we know those are legit and not scams? Which to choose ? there are alot too choose from. (Sweden here)

I'm a bit worried to order chips actually! Any advice?

For a European group buy, check out the SebastianJu thread. I placed a significant order there. He has identified himself by passport (to me as a prospective buyer). Also a very nice guy, seemed very capable of handling the organisational part of an enterprise like this.

https://bitcointalk.org/index.php?topic=187660

[Sophokles]

Nice work Ente... been waiting on someone with the right math skills to do this.

What specs for the heat sink do you think will work?

Ah, that stuff is easy once you figure it out! :-)

"0.5K/W" means, for example, that for each W[att] you throw at it, you have a K[temperature] difference of 5 degree. Like a 30 watt CPU cooled with a 5K/W heatsink would be 30*0.5 = 15 degree above the air temperature.
You add up all thermal resistances between the heat producer (CPU or ASIC core) and the surrounding (air). This is the thermal resistance of the cooling system.

Here we are at around 7K/W combined. Interestingly, the difference between air- and watercooling is neglicible, at an additional 0.25 K only.
This 7K/W is for each chip, it doesn't matter that we have 16 chips combined (as long as the heatsink covers the whole 10x10cm, doh!). This means, at 2 watts, that the silicon will be 14 degree warmer than ambient. Best case. Calculate 20 degree for some margin.

So, air or water?
Depends on your setup. If it's just a few chips, you won't have problems with air. As soon as your room would warm up, like, in summer with a thousand chips, you might prefer watercooling. Not because it cools better (it does not), but because you can cool the warm water somewhere else than where the chips are. Like having the miners inside and the radiator outside. Or warming your pool with it (use two watersystemns for that!).

Air? Any regular heatsink with a regular, slow spinning fan should be more than enough. A 1K/W heatsink isn't anything special, and that's with no fan! So, basically, as long as you have any aluminum piece with fins on it and have a little air blowing at it too, everything is sweet! :-)

In hindsight the whole calculation isn't really necessary. I didn't expect it to work out that nicely.

Homework:
Calculate similar systems with a 90w CPU (20x20mm), regular thermal compound and a bad/calm 0.5K/W heatsink. Max allowed CPU temperature is 70°C. How hot may the air in summer be at maximum, before the CPU starts cycling down its speed?

edit: Homework #2: What performance must a better heatsink have at least to work up to 30°C with the same CPU?

Ente

Hi!
schicke Aufstellung, vielen Dank. Nur eine kleine Korrektur:

0.5K/W" means, for example, that for each W[att] you throw at it, you have a K[temperature] difference of 5 degree. Like a 30 watt CPU cooled with a 5K/W heatsink would be 30*0.5 = 15 degree above the air temperature.

Die jeweils fett gedruckten 5 sollten 0.5 sein, oder? Ist so etwas verwirrend für jemanden, der sich zum ersten mal da reindenkt...

Gruß,
Sophokles

[pinocho]

Hi all!

I am looking for a local PCB maker to build a few Klondike boards. I guess it will be expensive buy it may be worth it.
I have just very basic electronics knowledge and would need answers to a few questions:

About K16:
- It is a 4-layer PCB, right?
- will the chips need heatsinks or fans? I can't find any in the parts list.
- are the github files enough for a competent maker to produce the PCB and solder all the components? Or maybe will they need some more specifications?
- Will the board need to be programmed or just start cgminer with correct parameters and it will work?
- there is a folder named protoboards/power. Is it necessary information for building the PCB or just for prototypes?

About the project status
- As stated in Readme: "This project is incomplete and in progress. There may be errors, mistakes, incomplete portions at this time. Do NOT use these -- project files to order circuit boards until they have been finished and confirmed to work."

I think the Avalon reference design is needed to complete the project. Did they release it yet? The modifications are likely to be in PCB/components or just firmware?

Very basic questions but I have not been able to figure the answers out.
I want to say THANK YOU to Bkkcoins for such a great work and for his generosity (please post a bitcoin address to receive some well deserved donations)

thanks again!
p.s :   I am based in Spain.
p.s. 2: I found the adress 

[wrenchmonkey]

Hi all!

I am looking for a local PCB maker to build a few Klondike boards. I guess it will be expensive buy it may be worth it.
I have just very basic electronics knowledge and would need answers to a few questions:

About K16:
- It is a 4-layer PCB, right?
- will the chips need heatsinks or fans? I can't find any in the parts list.
- are the github files enough for a competent maker to produce the PCB and solder all the components? Or maybe will they need some more specifications?
- Will the board need to be programmed or just start cgminer with correct parameters and it will work?
- there is a folder named protoboards/power. Is it necessary information for building the PCB or just for prototypes?

About the project status
- As stated in Readme: "This project is incomplete and in progress. There may be errors, mistakes, incomplete portions at this time. Do NOT use these -- project files to order circuit boards until they have been finished and confirmed to work."

I think the Avalon reference design is needed to complete the project. Did they release it yet? The modifications are likely to be in PCB/components or just firmware?

Very basic questions but I have not been able to figure the answers out.
I want to say THANK YOU to Bkkcoins for such a great work and for his generosity (please post a bitcoin address to receive some well deserved donations)

thanks again!
p.s :   I am based in Spain.
p.s. 2: I found the adress 

The design is not completed yet, and the files on the git should not be relied upon until the design has been tested and finalized.

You will need to program the boards, the designer is considering implementing the ability to flash over USB, but no promises.

Avalon has released the relevant information and it has been utilized. The current stage is to wait for developer chips, in order to finalize testing. There's not much that can be done with it until then. If you want to utilize the Avalon reference design, you still can. There are people offering to create Avalon clones.

Heatsinks will be required. Much of the recent crosstalk in this thread has been in regard to designing and sourcing heatsinks. You will need to source your own, or get on board with a group buy.

[Dunkelheit667]

...
p.s :   I am based in Spain.
...

The List of Avalon-ASIC-Miner-Developers and Assembler might help to find some upcoming Klondike PCB sources in the EU. Guess going this direction should be a bit more hassle free.

[pinocho]

...
p.s :   I am based in Spain.
...

The List of Avalon-ASIC-Miner-Developers and Assembler might help to find some upcoming Klondike PCB sources in the EU. Guess going this direction should be a bit more hassle free.

Thank you Dunkelheit667 and wrenchmonkey. I will check both threads again.

BR.

[Ente]

Nice work Ente... been waiting on someone with the right math skills to do this.

What specs for the heat sink do you think will work?

Ah, that stuff is easy once you figure it out! :-)

"0.5K/W" means, for example, that for each W[att] you throw at it, you have a K[temperature] difference of 5 degree. Like a 30 watt CPU cooled with a 5K/W heatsink would be 30*0.5 = 15 degree above the air temperature.
You add up all thermal resistances between the heat producer (CPU or ASIC core) and the surrounding (air). This is the thermal resistance of the cooling system.

Here we are at around 7K/W combined. Interestingly, the difference between air- and watercooling is neglicible, at an additional 0.25 K only.
This 7K/W is for each chip, it doesn't matter that we have 16 chips combined (as long as the heatsink covers the whole 10x10cm, doh!). This means, at 2 watts, that the silicon will be 14 degree warmer than ambient. Best case. Calculate 20 degree for some margin.

So, air or water?
Depends on your setup. If it's just a few chips, you won't have problems with air. As soon as your room would warm up, like, in summer with a thousand chips, you might prefer watercooling. Not because it cools better (it does not), but because you can cool the warm water somewhere else than where the chips are. Like having the miners inside and the radiator outside. Or warming your pool with it (use two watersystemns for that!).

Air? Any regular heatsink with a regular, slow spinning fan should be more than enough. A 1K/W heatsink isn't anything special, and that's with no fan! So, basically, as long as you have any aluminum piece with fins on it and have a little air blowing at it too, everything is sweet! :-)

In hindsight the whole calculation isn't really necessary. I didn't expect it to work out that nicely.

Homework:
Calculate similar systems with a 90w CPU (20x20mm), regular thermal compound and a bad/calm 0.5K/W heatsink. Max allowed CPU temperature is 70°C. How hot may the air in summer be at maximum, before the CPU starts cycling down its speed?

edit: Homework #2: What performance must a better heatsink have at least to work up to 30°C with the same CPU?

Ente

Hi!
schicke Aufstellung, vielen Dank. Nur eine kleine Korrektur:

0.5K/W" means, for example, that for each W[att] you throw at it, you have a K[temperature] difference of 5 degree. Like a 30 watt CPU cooled with a 5K/W heatsink would be 30*0.5 = 15 degree above the air temperature.

Die jeweils fett gedruckten 5 sollten 0.5 sein, oder? Ist so etwas verwirrend für jemanden, der sich zum ersten mal da reindenkt...

Gruß,
Sophokles

Tatsächlich, gut aufgepasst! :-)
I started with a 5K/W example. This is such a bad heatsink that it results in odd numbers. When changing to 0.5K/W I didn't edit all numbers.
Thanks for the note!

Also, the answer to your homework:
Don't cheat, calculate it by yourself! :-P
--->#1: This bad heatsink with such a powerful CPU would only work up to 11°C! *giggle* <---
--->#2: For that CPU you would need a 0.28K/W or better (=smaller number) heatsink <---

Ente

[Bicknellski]

Ente,

Cumon Bra.... help.

Lazy I am.

[fasmax]

@ BkkCoins
How many bytes of data to you have to shift into each Avalon chain to configure the chips?

Off the top of my head I think it's 32 midstate, 24 pre-calc, 12 data, 8 clk cfg and with 8 chips/bank 32 bytes nonce data. Maybe it's not 12 bytes data. I don't have it in front of me now but I recall the Avalon driver having 12 bytes in it's task structure.

That would be 84 same for both banks + 32 different = 116 bytes.
At 4Mbps that's 29uS, though I think it will take a bit longer due to software clocking limits.

edit: oops. That's bytes not bits. x8 = 232 uS.

[/quote]
How big of a performance hit would there be if a software clocking algorithm took 500uS to 600uS to load the Avalon chips?
Thanks 

[BkkCoins]

Just back from Bkk. I have some news and will post a couple replies to posts above shortly. I have to have a shower and rest a bit first.

[Bicknellski]

I think you might have one heat sink and a RAY GUN in hand... I hope at least.

[BkkCoins]

Ok. Back again, for my 2nd try at this (first one was wiped by the board software after 15 minutes typing it out!).

I picked up a number of things but the highly desired PIC chips had not yet arrived. Disappointed. I know they're overdue and should be there any day now. So I'll be calling in and going again as soon as they are there. I had to go this time due to other demands and was hoping they arrived before me. No luck.

But the good news is from forum member chaoztc who, just before I left, bread boarded up a couple of the same PICs and tested out the data signalling. He had good results with prelim code that transfers bursts of 104 bytes from one PIC to the other using my planned methods (software output, NOR gate, delay and UART input). Here's a few photos from him:

Breadboard showing NOR gates and PICs.


Burst of data between PICs.


Clock (yellow) and data (green) after NOR gate and RC delay going into UART.


This is great advance work and he sent me the sample code to work from going forward. I believe he's also using some info I sent his way to optimize for faster speeds.

The IR Thermometer arrived and works great. Thank You, Bicknellski.

No heat sinks qrrived but I did check a few shops in Bkk and got some useful stuff there. I have some small heat sinks for the K1 now, and a larger double size 115mm x 254mm x 30mm heat sink for the K16. I'll try mounting 2x K16 on this but it could be cut down for 2 units. This would work using the method where PCB mounts against heat sink as support member. They're going to get me a price on 400mm long for a 4x bar. The way these places work - I know they are buying from another local source for about half the price. I paid $6 for this double heat sink, so that's $3 each. I bet some wholesaler in Bkk has them for $3 each, $1.50 per K16. Hard to find out where. Will try to post some photos later but the ones I got look much the same as other posted here.

I picked up several tools and fans, and various bits which I'll be testing out soon. I expect to order the scope today thanks to KS who arranged a bitcoin sale for me and made a large donation in US$ to get this going. For as much as I love Bitcoin it's still a hassle to transfer in/out of $$.

How big of a performance hit would there be if a software clocking algorithm took 500uS to 600uS to load the Avalon chips?
Thanks 

A 300uS loss on 0.9 S work cycle (assuming 16 chips) would be 0.03%, so even if I can't get it fastest possible choaztc has already shown a speed that will make other friction much greater than not being able to push data at full speed. I'm confident we'll get quite close and if the ASIC is super picky about input timing I have a back up plan that may get us bang on 125nS timing, but is a bit tricky software wise.

Air? Any regular heatsink with a regular, slow spinning fan should be more than enough. A 1K/W heatsink isn't anything special, and that's with no fan! So, basically, as long as you have any aluminum piece with fins on it and have a little air blowing at it too, everything is sweet! :-)

In hindsight the whole calculation isn't really necessary. I didn't expect it to work out that nicely.

Ente

Spot on Ente. I think from your calcs and the Avalon photos we can be pretty sure that a heat sink is needed, and air flow is needed, but after that it's not going to be critical just how much or how big the fins are. Good board -> heat sink contact is our main concern but I think we'll be fine there.

[marto74]

How a single K16 with heatsink and fan will look

[steamboat]

How a single K16 with heatsink and fan will look

It's eerie how similar our designs are.

[BkkCoins]

How a single K16 with heatsink and fan will look

Nice! Those look to be 100mm fans. I've only found 80mm and 120mm locally.
Well, I'm sure they exist out there.

[marto74]

How a single K16 with heatsink and fan will look

It's eerie how similar our designs are.

So there are 2 options:
Both We are doing great
Both made a mistake

We'll see when some chips are here working and distributing the heat

[erk]

How a single K16 with heatsink and fan will look

Nice! Those look to be 100mm fans. I've only found 80mm and 120mm locally.
Well, I'm sure they exist out there.

SilenX do 100mm  http://www.silenx.com/quiet.fans.asp?sku=efx-10-12

There are a lot of 92mm fans out there, 100mm not so common.

[steamboat]

How a single K16 with heatsink and fan will look

It's eerie how similar our designs are.

So there are 2 options:
Both We are doing great
Both made a mistake

We'll see when some chips are here working and distributing the heat

This is true I'm fairly confident this design will work, even with an ultraquiet low cfm fan.

[Bicknellski]

SCYTHE 100mm




SILENX 100mm

[BkkCoins]

I love that they put two sets of holes on those fans. Great idea. Why no prices on their info?

** News Flash **
Just got an email that my K1 test boards have shipped out.
I'd expect them here in 6-7 days then. Job #1 - get everything ready for that.
And get the K16 finalized and out.