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Author Topic: ZTEX USB-FPGA Modules 1.15x and 1.15y: 215 and 860 MH/s FPGA Boards  (Read 174058 times)
DeathAndTaxes
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Gerald Davis


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March 19, 2012, 02:57:19 PM
 #421

FPGA on the black market ... LOL.

Nobody said BLACK.  The term is gray market.  BFL almost certainly got their super cheap chips via gray market channels.

Say a company orders 10,000 chips but turns out demand isn't there, a broker buys them below costs and then shops them around.  Along the same line wholesales will often "unofficially" sell product to brokers below retail price.  Sometimes manufacturer will sell chips below retail to a broker rather than discount them publicly.

Depending on connections, volume, and flexibility it is possible to find chips below retail sometimes significantly below retail.
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Dhomochevsky
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March 19, 2012, 03:46:53 PM
 #422

Hmm. THE MOAR YOU KNOW.

This gets me thinking - so far the chips sold solely for mining boards I'm pretty sure are in the low thousands. When FPGA mining really takes off and various mining solutions will be available from an assortment of manufacturers, should we expect an increase in price due to demand? Seeing how the GPU market wasn't affected by bitcoin mining, I'd hazzard a no, but still...
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March 19, 2012, 04:16:36 PM
 #423

Quote from: Dhomochevsky
When FPGA mining really takes off and various mining solutions will be available from an assortment of manufacturers, should we expect an increase in price due to demand? Seeing how the GPU market wasn't affected by bitcoin mining, I'd hazzard a no, but still...

Not a precise guesstimate "really takes off",  but I don't think mining will ever come close to the kind of market that some FPGAs are designed for,
like consumer markets or large markets like network switches, etc. I agree, don't think prices will change due to BTC mining.

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March 19, 2012, 04:19:45 PM
 #424

I have a question about the fan. Is it possible to get the spec, seems to be a 40mm and I hope that its not necessary to run it at full speed. Others have mentioned that their setup is silent. Anyone care to share their noise-levels and what you think.
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March 19, 2012, 04:26:16 PM
 #425

Quote from: ztex
As far I know Icarus uses the FPGA's that are available on the gray marked.

Do you know of any gray market chip dealers? Govt. surplus?

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Gerald Davis


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March 19, 2012, 06:01:09 PM
 #426

Hmm. THE MOAR YOU KNOW.

This gets me thinking - so far the chips sold solely for mining boards I'm pretty sure are in the low thousands. When FPGA mining really takes off and various mining solutions will be available from an assortment of manufacturers, should we expect an increase in price due to demand? Seeing how the GPU market wasn't affected by bitcoin mining, I'd hazzard a no, but still...

Probably not.  The FPGA market is in the tens of billions.  Smaller than GPU market but still magnitudes larger than Bitcoin Mining.  If Mining ever got so large that say annual says of mining hardware was $10M+ you likely would see sufficient demand for someone to take the risk of full custom ASIC and take nearly 100% marketshare.  Once that happens no FPGA will be able to compete so even if Bitcoin is magnitudes larger it won't have any effect on FPGA pricing other than many short term supply disruptions but given how price sensitive miners are I doubt even that is likely.
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March 19, 2012, 06:25:05 PM
 #427

I have a question about the fan. Is it possible to get the spec, seems to be a 40mm and I hope that its not necessary to run it at full speed. Others have mentioned that their setup is silent. Anyone care to share their noise-levels and what you think.

I replaced all my fans with Scythe Kaze minis. One fan failed (got very noisy) because i blew air on the board with a 92mm fan, diagonal from above. Not very clever i know ! That destroyed the bearing in less than 2 months Grin The minis are a bit quieter but they don't deliver the same airflow as the stock fans. Scythe is 14 dB/A, 4,11 CFM, Xilence (stock) 19 db/A, 5,28 CFM.

The stock fans are a good balance between noise and effective cooling for a stand-alone board. Since i use additional fans to cool my units and the noise was too loud, i went with the minis. Very happy so far.

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March 20, 2012, 12:06:46 AM
 #428

In my opinion an optimal cooling solution for a larger cluster would be as follows:

- put a number of boards in a single case
- establish proper airflow through case
- individual boards using proper heat sinks
- no fan on individual boards
- airflow forced through heat slinks
  (ie. space around them tight so air can't go around)

I will do some experimenting with this in the near future.

Does anybody know a "formula" of what kind of airflow (amount of air) we need to cool X watt of heat dissipation? I know this probably depends on the heat sinks too and the surface, but I am looking for some kind of textbook formula to get a ballpark figure - so that I don't have to start off a good guess.
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March 20, 2012, 01:10:20 AM
 #429

In my opinion an optimal cooling solution for a larger cluster would be as follows:

- put a number of boards in a single case
- establish proper airflow through case
- individual boards using proper heat sinks
- no fan on individual boards
- airflow forced through heat slinks
  (ie. space around them tight so air can't go around)

I will do some experimenting with this in the near future.

Does anybody know a "formula" of what kind of airflow (amount of air) we need to cool X watt of heat dissipation? I know this probably depends on the heat sinks too and the surface, but I am looking for some kind of textbook formula to get a ballpark figure - so that I don't have to start off a good guess.


You can start by looking at the air thermal transfer rate + surface area formulas. I guess nothing ready as every custom case is... well custom. I'd say just build it and test it.
Just remember that air is actually very poor in thermal transfer, you can actually use air as an insulator if you can stop it from moving ...

I've been thinking of doing the same thing, designed a case, based on single 3W 230mm fan after i get my first boards and got a bit of time on my hands, going to design in 3d and then print the casings. Testing will show how well it works.

But i'm still of a month or couple before doing that, other things to do in regards of mining first.

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March 20, 2012, 08:30:15 AM
 #430

Totally agree... One big silent fan instead of lots of humming small ones. I need something like this:

        / * FPGA
       /  * FPGA
FAN=   * FPGA
       \  * FPGA
        \ * FPGA

Like a big vacuum cleaner piece. Wonder if it exists?

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ztex
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ZTEX FPGA Boards


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March 20, 2012, 08:33:46 AM
 #431

In my opinion an optimal cooling solution for a larger cluster would be as follows:

- put a number of boards in a single case
- establish proper airflow through case
- individual boards using proper heat sinks
- no fan on individual boards
- airflow forced through heat slinks
  (ie. space around them tight so air can't go around)

I can confirm that this will work. I used this method for cooling a couple of 1.15d FPGA boards (with smaller heat sinks).


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March 20, 2012, 02:07:01 PM
 #432

Totally agree... One big silent fan instead of lots of humming small ones. I need something like this:

        / * FPGA
       /  * FPGA
FAN=   * FPGA
       \  * FPGA
        \ * FPGA

Like a big vacuum cleaner piece. Wonder if it exists?

That wouldn't work but something like this would:

 ______
F FPGA
A FPGA
N FPGA
  -------

and 2-3 side by side. Depending upon the fan size, this would create a 2x2 or 3x3 box, depending upon spacing ofc.

That funnel would fail to work because too small pressure differentiation and airflow speed, for the funnel to force the airflow to spread. Pressure being the more important factor.


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rupy
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March 20, 2012, 03:28:59 PM
 #433

Totally agree... One big silent fan instead of lots of humming small ones. I need something like this:

        / * FPGA
       /  * FPGA
FAN=   * FPGA
       \  * FPGA
        \ * FPGA

Like a big vacuum cleaner piece. Wonder if it exists?

That wouldn't work but something like this would:

 ______
F FPGA
A FPGA
N FPGA
  -------

and 2-3 side by side. Depending upon the fan size, this would create a 2x2 or 3x3 box, depending upon spacing ofc.

That funnel would fail to work because too small pressure differentiation and airflow speed, for the funnel to force the airflow to spread. Pressure being the more important factor.



Yes but the funnel would slim out on the other diagonal, to even the airflow. Like so:

Topview:

          /  FPGA
        -    FPGA
             FPGA
FAN        FPGA
             FPGA
        -    FPGA
          \  FPGA

Sideview:

        -
          \
FAN        FPGA
          /
        -

So the entrance is circular and the exit is a very thin and long rectangle.

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March 20, 2012, 04:28:18 PM
 #434

What I have noticed using 10 board vertical stacking is that a thermal stratification occurs inside the case. Not the air, but material and pcb. Higher boards have higher temps. Horizontal might be a more efficient method if running in a high ambient temp area. I put fastest of the boards in top slot and installed the rest in order going down. 10 boards running in cluster mode have had a combined speed of 2077.9 MH/s for weeks now on P2Pool.
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March 20, 2012, 05:28:37 PM
 #435

What I have noticed using 10 board vertical stacking is that a thermal stratification occurs inside the case. Not the air, but material and pcb. Higher boards have higher temps. Horizontal might be a more efficient method if running in a high ambient temp area. I put fastest of the boards in top slot and installed the rest in order going down. 10 boards running in cluster mode have had a combined speed of 2077.9 MH/s for weeks now on P2Pool.

Yes, It's best to not stack vertically or inline (Turbor). Best is bottom up, heat rises.

Another solution to the above is to build a web of small pipes, one to each heatsink. Like an inverted octopus vacuum cleaner!

The point here is that you don't need a large area of air if your air is fast and/or cold.

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March 20, 2012, 07:25:46 PM
 #436

So the entrance is circular and the exit is a very thin and long rectangle.

Maybe you should have a look at cross flow fans?
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March 20, 2012, 07:48:34 PM
 #437

So the entrance is circular and the exit is a very thin and long rectangle.

Maybe you should have a look at cross flow fans?

Hm, no but thanks for the suggestion.

I'm actually thinking about aquarium air pumps now for the "octopus" solution... but I know the final solution will be convection, even if it means wearing my chips a little.

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March 20, 2012, 09:26:00 PM
 #438

Totally agree... One big silent fan instead of lots of humming small ones. I need something like this:

        / * FPGA
       /  * FPGA
FAN=   * FPGA
       \  * FPGA
        \ * FPGA

Like a big vacuum cleaner piece. Wonder if it exists?

I've been thinking about mounting three to six of them inside of the hard drive tray in my case. It has hot swap trays with 3.5 and 2.5 mounts already designed into them. The front of the case has a 230mm fan that blows directly on it.

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March 20, 2012, 09:50:01 PM
 #439

ZTEX board support has finally hit the MPBM testing branch!

Available here: https://github.com/TheSeven/Modular-Python-Bitcoin-Miner/tree/testing

I appreciate any feedback!

If you run into any issues, please contact me on IRC: #mpbm on irc.freenode.net

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March 22, 2012, 10:33:42 PM
 #440

Would love to test this.... But:

1. How Safe is it ? (i don't want my boards to blow up .....)
2. Is there a "how to" aviable (for a windows guy that moved to MAc OSX) Cheesy

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