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Topic: [GAUGING INTEREST] H-Card Mini Group fab - page 2. (Read 8022 times)

hero member
Activity: 658
Merit: 500
CCNA: There i fixed the internet.
BOM is underway. check 3rd OP for details
hero member
Activity: 658
Merit: 500
CCNA: There i fixed the internet.
April 26, 2014, 12:48:06 AM
#9
I would be interested in a few. I just had two h-cards die on one of my rigs, and it looks like another card is hashing ridiculously poorly on a different rig so it's probably going to kick the bucket soon. I just hope that they will hash roughly equivalent to the 16 chip cards. I'd be happy with 25 GH. The thing is, they'd have to be pretty cheap to justify reinvesting in bitfury hardware rather than just saying screw it and go buy a bitmain or A1 based product.

I've come to the conclusion that v1.2 cards are just too poorly built to run 24/7.

If I might inquire how were the chips on the two dead cards doing before communication death?
legendary
Activity: 3080
Merit: 1080
April 25, 2014, 05:55:13 PM
#8
I would be interested in a few. I just had two h-cards die on one of my rigs, and it looks like another card is hashing ridiculously poorly on a different rig so it's probably going to kick the bucket soon. I just hope that they will hash roughly equivalent to the 16 chip cards. I'd be happy with 25 GH. The thing is, they'd have to be pretty cheap to justify reinvesting in bitfury hardware rather than just saying screw it and go buy a bitmain or A1 based product.

I've come to the conclusion that v1.2 cards are just too poorly built to run 24/7.
hero member
Activity: 658
Merit: 500
CCNA: There i fixed the internet.
April 25, 2014, 01:15:44 PM
#7
The better method would be to make 16-chip boards by the official spec, and using the newer revision of chip that should allow each 16-chip board to push ~50GH.

The 8-chip board just results in more slots on the m-board being filled which is an issue if you don't sell m-boards to go with it.  just my 2c

Hash rate is very dependent on amperage an voltage and with positive correlations to both.

A rev.2 16 chip board wouldn't reach 50 easily with out some serious heat extraction and over clocking

It would be no problem at all if another 30A power phase was added to the board. But then you have 70+ watts to pull out of a board

That's some of the rationale I used when deciding 8 vs 16

I'm wanting to get the max out of these chips and and doubling the amp ration they each get is one way to do so.

If I knew that 16 could crunch along at 50 It would be a no brainer decision. But in most real life situations a rev2 16 ASIC card with heatsinking on the vrm and each ASIC
OV'ed to 0.833 would probably pull ~35-40 maybe 43


TL;DR: a 16 chip card won't run at the same per chip hashrate as an 8 chip card using the same 30A  power supply.
This is because of thermal and electrical constraints
legendary
Activity: 2128
Merit: 1005
ASIC Wannabe
April 25, 2014, 10:35:21 AM
#6
The better method would be to make 16-chip boards by the official spec, and using the newer revision of chip that should allow each 16-chip board to push ~50GH.

The 8-chip board just results in more slots on the m-board being filled which is an issue if you don't sell m-boards to go with it.  just my 2c
hero member
Activity: 658
Merit: 500
CCNA: There i fixed the internet.
April 25, 2014, 12:11:31 AM
#5
I still run 2 rigs with open spots. I would be interested in trying 2 out, depending on the price.
How many GH/s per board?

well going off figures obtained from projects like the NFY: using the same 30A vrm to power half the # of chips would allow 3.75A per chip. and we know how amp hungry these guys are Smiley

the NFY using Rev.2 chips i got to acheive 2.8-3.0G with [email protected] so, without having one immediately to test. i would say in the neighborhood of 22-25Ghash would be a safe bet. the ones kaerf made used the 20A version of the VRM and those produced ~20ghash. who knows we may be pleasantly surprised and get 25+ in which case half the chips, same hashrate as the regular 16 chip cards


see https://bitcointalksearch.org/topic/m.3259455 for his results
legendary
Activity: 1593
Merit: 1004
April 24, 2014, 11:49:08 PM
#4
I still run 2 rigs with open spots. I would be interested in trying 2 out, depending on the price.
How many GH/s per board?
hero member
Activity: 658
Merit: 500
CCNA: There i fixed the internet.
April 24, 2014, 09:46:02 PM
#3
Reserved: for pricing breakdown and additional notes.





All interested please leave a comment with Qty desired. all comments are non binding and may be retracted at any time for any reason*


FOR ALL Parties interested in the present standing of the Bill of Materials and Estimates, here is a link to a publicly commentable spreadsheet which includes some scratchpad math used in arrival at prices.

https://docs.google.com/spreadsheets/d/1oAkDHg9hR94NZVTgnxD9AuBUls8syuhw3IGAKbLQkPc/edit#gid=42212007







*until a formal list is compiled, and BOM lists are ordered.
hero member
Activity: 658
Merit: 500
CCNA: There i fixed the internet.
April 24, 2014, 09:45:52 PM
#2
Privately I have been gearing up for a small-ish run of 10 boards with
  • pcbs fabbed by seeedstudio's fusion pcb service incl: free e-test and ENIG gold finish on connector for durability.
  • Polyimide (Kapton) Stencil from OharaRP
  • Parts lists filled with the most cost effective split across Digikey and Mouser

so i figured i would extend the opportunity to the public.

Depending on the number of interested parties, i may continue this route. Or if there are enough interested I will come up with a more formal, professional fab sequence utilizing an assembly house.


UPDATE: pricing breakdown of the bare boards and BOM will be listed in various order quantities..shortly
hero member
Activity: 658
Merit: 500
CCNA: There i fixed the internet.
April 24, 2014, 09:45:39 PM
#1
H-CARD Mini:
    The h-card mini is the OSHW offspring of a wonderful forum member here, Kaerf. to summarize their efforts: they had received a few regular v1.2 H-cards with several dead chips. instead of mailing them back for RMA, they used the available schematics from MBP/BFSB for the v1.2, which normally holds 16 Bitfury ASICs, and redesigned it to hold 8 ASICS and accommodate mounting holes for standard 40mm2 northbridge heatsinks.

Images courtesy of Kaerf

Album
http://imgur.com/a/5Ebiw

Blank board


Standard 40mm2 heatsinks



What am I proposing?

I am gauging interest to see how many folks out there in the community with unfilled m-boards who would like to fill them with something now that MBP/BFSB are both out of stock on these cards.

Who am I?
I am a frequenter of the forums and partaker of several past group buys from distributors such as kosmokramer, Bitcoinvalet, Xian, and the well known designer of the Nanofury devices, vs3.

Ive been on the purchasing end of group buys before but this is my first venture into leading one.
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