bASIC - speed boost - 54G now 72G, 27G now 36G (~)

[Roy Badami]

You should be fine drawing 120W through the Molex connector even with 18 gauge wire. If your PSU is pretty standard with the first 4pin being about 1.5ft along the cable, you'll end up with a round trip resistance of a little under 15 milliohms for the single 12V and dual ground wires. You'd only lose 0.15V across the wire, which really isn't a concern. Wire heating should also not really be an issue unless your application is extreme.

It's not the wire run I'm worrying about, it's the reduced contact area between the wire and the connector when you crimp it.

Molex only rates the connectors for the full current draw when you use 16AWG - see http://www.molex.com/pdm_docs/ps/PS-8981-4M4P.pdf

roy

[MrTeal]

You should be fine drawing 120W through the Molex connector even with 18 gauge wire. If your PSU is pretty standard with the first 4pin being about 1.5ft along the cable, you'll end up with a round trip resistance of a little under 15 milliohms for the single 12V and dual ground wires. You'd only lose 0.15V across the wire, which really isn't a concern. Wire heating should also not really be an issue unless your application is extreme.

It's not the wire run I'm worrying about, it's the reduced contact area between the wire and the connector when you crimp it.

Molex only rates the connectors for the full current draw when you use 16AWG - see http://www.molex.com/pdm_docs/ps/PS-8981-4M4P.pdf

roy

Do you have a reference that indicates the reduced rating is caused by a smaller crimped contact area? The effect won't actually be as great as you're indicating; you have almost the same contact area crimping to 18 gauge as you do 14 gauge.

[Roy Badami]

Do you have a reference that indicates the reduced rating is caused by a smaller crimped contact area? The effect won't actually be as great as you're indicating; you have almost the same contact area crimping to 18 gauge as you do 14 gauge.

No, sorry, that's pure speculation on my part; I just couldn't think of any other reason why Molex would derate the connectors for 18AWG and smaller...

roy

[Roy Badami]

@MrTeal:

Also, just did the math and the figures match perfectly.  18AWG has almost exactly 20% smaller diameter than 16AWG, and hence 20% smaller circumferance.  I don't know exactly how 8981 connectors are crimped, but wouldn't that result in 20% smaller contact area?

And Molex derate the connector by 20% (i.e. from 10A to 8A)

[MrTeal]

@MrTeal:

Also, just did the math and the figures match perfectly.  18AWG has almost exactly 20% smaller diameter than 16AWG, and hence 20% smaller circumferance.  I don't know exactly how 8981 connectors are crimped, but wouldn't that result in 20% smaller contact area?

And Molex derate the connector by 20% (i.e. from 10A to 8A)

The wire doesn't stay round when you crimp it, it ovals out. Check out my super accurate 60 second paint drawing.


Maybe accuracy could be better, but you get the idea. The smaller diameter the wire, the more it deviates from round and the more surface area you get relative to a circle.

[Roy Badami]

The smaller diameter the wire, the more it deviates from round and the more surface area you get relative to a circle.

Ah, OK, that sounds plausible.  Still, there has to be some reason why Molex chose to specify different ratings for different wire gauges and for whatever reason, they've rated an 8981 on 18AWG (the ATX standard) at 8A.   It's difficult to know exactly how the current density will be distributed in the crimp region...

roy

[AfricanHunter]

Sorry for the OT post but didnt want to start another thread on this;

Does anyone know the power supply specs and connection requirements for the 72 GH bASIC? Trying to spec out a PSU cable from Cablez but he says he doesnt have enough info to feel confident on setup. Any help appreciated. Feel free to pm me

[Morblias]

Sorry for the OT post but didnt want to start another thread on this;

Does anyone know the power supply specs and connection requirements for the 72 GH bASIC? Trying to spec out a PSU cable from Cablez but he says he doesnt have enough info to feel confident on setup. Any help appreciated. Feel free to pm me

The exact power numbers have not been released yet so none of us know. Hopefully soon we can get the numbers and start throwing BTC at Cablez

[MeSarah]

Hey Cablez,bASIC's guys have a question & need your help!!!!!

Posted by Roy Badami :

"I'm rather worried about this.  80-120W @ 12V is 6.7-10A.   steve contacted Seasonics in another thread and we know that Seasonic PSUs can only supply a maximum of 7A on their peripheral (8981) connectors - i.e. what's commonly called a Molex connector.  That's only 84W @ 12V.  Other PSUs are unlikely to be any better.  So we seem to have a situation where it will quite likely be impossible to safely power the bASIC from the Molex connector on even a premium quality ATX PSU, but will instead require a custom cable to connect the Molex connector on the bASIC to a PSU connector with multiple 12V rails pins, such as a PCI-E connector or CPU connector.  

This seems far from ideal - I think we really need the bASIC to have a connector with multiple 12V rails pins, such as PCI-E.  I'm not sure how easy it will be to source 10A barrel connectors, either.  Josh has said that BFL have been having difficulty sourcing high current barrel connectors [ETA: and Cablez has likewise said he's had difficulty finding barrel connectors rated at 10A] although given BFL's lower (stated) power specs, and the fact that they seem to be planning to go with 13-14V for their wall warts, connector power draw is probably less of an issue for them.

I'd really like to be sure that the bASIC will come with a connector that is safe to run at 10A for extended periods of time without running so hot that it melts or otherwise creates a safety hazzard. Some clarification on this would be most welcome.  The Molex solultion works fine on the MMQ because it only consumes 40W - which is a current draw of just 3.3A.  I just don't see how it's going to safely work for a miner that's going to consume 2-3 times the power. [ETA: unless you use two of them, of course]"

https://www.btcfpga.com/forum/index.php?topic=104.30

Show'em what you got dude!!!!!!!!!!!!!  

Edit:Here's what we ALL can use 

https://bitcointalk.org/index.php?topic=74397.0

If your running a bASIC product from Tom and your house burns down, how does that affect your ROI? Lets hope that no one will die.

[Starlightbreaker]

ok, who unbanned the above moron?

[miter_myles]

If your running a bASIC product from Tom and your house burns down, how does that affect your ROI? Lets hope that no one will die.

[bcpokey]

If someones ignore button is yellow, does that mean tons of people have ignored them and the forum is suggesting I do so also?

I've only seen two people with yellow Ignore buttons now, electricmucus and MeSarah

[Jack1Rip1BurnIt]

If someones ignore button is yellow, does that mean tons of people have ignored them and the forum is suggesting I do so also?

I've only seen two people with yellow Ignore buttons now, electricmucus and MeSarah

Yes, the more people push the ignore button the more the button turns that funky piss yellow.

[Unacceptable]

Hey Cablez,bASIC's guys have a question & need your help!!!!!

Posted by Roy Badami :

"I'm rather worried about this.  80-120W @ 12V is 6.7-10A.   steve contacted Seasonics in another thread and we know that Seasonic PSUs can only supply a maximum of 7A on their peripheral (8981) connectors - i.e. what's commonly called a Molex connector.  That's only 84W @ 12V.  Other PSUs are unlikely to be any better.  So we seem to have a situation where it will quite likely be impossible to safely power the bASIC from the Molex connector on even a premium quality ATX PSU, but will instead require a custom cable to connect the Molex connector on the bASIC to a PSU connector with multiple 12V rails pins, such as a PCI-E connector or CPU connector.  

This seems far from ideal - I think we really need the bASIC to have a connector with multiple 12V rails pins, such as PCI-E.  I'm not sure how easy it will be to source 10A barrel connectors, either.  Josh has said that BFL have been having difficulty sourcing high current barrel connectors [ETA: and Cablez has likewise said he's had difficulty finding barrel connectors rated at 10A] although given BFL's lower (stated) power specs, and the fact that they seem to be planning to go with 13-14V for their wall warts, connector power draw is probably less of an issue for them.

I'd really like to be sure that the bASIC will come with a connector that is safe to run at 10A for extended periods of time without running so hot that it melts or otherwise creates a safety hazzard. Some clarification on this would be most welcome.  The Molex solultion works fine on the MMQ because it only consumes 40W - which is a current draw of just 3.3A.  I just don't see how it's going to safely work for a miner that's going to consume 2-3 times the power. [ETA: unless you use two of them, of course]"

https://www.btcfpga.com/forum/index.php?topic=104.30

Show'em what you got dude!!!!!!!!!!!!!  

Edit:Here's what we ALL can use  

https://bitcointalk.org/index.php?topic=74397.0

If your running a bASIC product from Tom and your house burns down, how does that affect your ROI? Lets hope that no one will die.

It's called "Home Owners Insurance",hope you've got it  

Great discussion on power & cable options,Thanks!!!

Why so many ignores for MeSarah    Look at the post history   He's also a BFL "asshamster" (trademark protected) 

[itsgoldbaby]

https://www.btcfpga.com/forum/index.php?topic=125.0

"Hello

I really can't express the depth of how incredibly pissed off I am about this project (as I am sure you are as well). After hours of meetings and discussions today with my engineering team I don't see any possible way we will be able to release the bASIC before mid January.

When I first planned this project I was quoted a 2 week design time for the board itself and that was the time we planned for. Due to a conflict of interest we had to find a new design firm, one that came highly recommended and is well known and respected / reputable. This new design firm although incredibly talented is equally thorough and things are taking longer than I had expected.

I am planning now on a mid January release date and I deeply apologize to all of my customers, and I do not blame anyone at all who wants to just cancel their order and get a full refund.

I also think it's very important for everyone to know that Dave is just an employee of BTCFPGA he does not own any part of ownership of this company and cannot be blamed for its problems. I take full personal responsibility for this delay and any other problems anyone has encountered with our company.


REFUNDS:
For those who cannot wait until January and want a refund (or for any other reason) I do not blame you what so ever, and I encourage anyone who has any doubts of this project to please request a refund immediately. We will begin issuing refunds as early as this evening, so for those who have requested a refund you will receive it over the next 1-2 days.

Also please keep this in mind - if you want a refund please just request one by sending an email to dave@bitcoinasic.net (he now has the power to issue refunds) You will receive it MUCH faster than by requesting a charge-back through your bank.

Please accept my sincere apologies for not being as available to you as I would like to be,  this whole situation really has me at wits end, however I WILL be available tomorrow 11/28 in afternoon."

[GenTarkin]

Next time, dont release get our hopes up about a release date you know you cant pull off. I mean fuck, first BFL, now bASIC...
Really guys?!?! How about, once you actually get chips & boards & assembled .. along w/ numbers out to the community.. Then FUCKING CLAIM YOU CAN SHIP! But not before then.
This is pirateat40 all over again except this time holding our fucking BTC for something these companies cant even prove to us customers..exists....!
Fuck that! Horrible business ethics.

[MeSarah]

Sock puppet identified, itsgoldbaby.

[itsgoldbaby]

Sock puppet identified, itsgoldbaby.

Cool, not sure of the full meaning of this though. If you mean I have ordered from bASIC, your right. I posted the message from the btcfpga over to here for people to see, as well. Thought people might like to see the "news". Have fun with your trolling mate, good luck.

[MeSarah]

@ itsgoldbaby, my apologies. I missed your quotation marks. It is interesting news. I think most people who were not diluting them self ever believed Tom could make the ship date he told the community.

[AfricanHunter]

Sorry for the OT post but didnt want to start another thread on this;

Does anyone know the power supply specs and connection requirements for the 72 GH bASIC? Trying to spec out a PSU cable from Cablez but he says he doesnt have enough info to feel confident on setup. Any help appreciated. Feel free to pm me

The exact power numbers have not been released yet so none of us know. Hopefully soon we can get the numbers and start throwing BTC at Cablez

Thanks for the info. Any timeline that you are aware of for the info to be released?