Bitcoin Forum
December 11, 2017, 12:33:41 AM *
News: Latest stable version of Bitcoin Core: 0.15.1  [Torrent].
 
  Home Help Search Donate Login Register  
  Show Posts
Pages: « 1 ... 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 [55] 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 ... 118 »
1081  Bitcoin / Hardware / Re: Quad XC6SLX150 Board - Initial Price 400/$640/520 on: May 18, 2012, 04:42:30 PM
I'm not arguing that a super high density board would be the ultimate in high density mining. Point is there is a sweet spot for a distributor between low volume sales and profit. With this board design they can make a high volume of boards, and reduce their per-unit overhead. Meaning better profit margins. A super high density board would allow better density, but would likely have much lower sales volumes (requiring thicker markup to make back their R&D overhead and such). Also manufacturing yield is easier to control on smaller boards.

Wrong. These manufacturers are already building 8x and 16x boards at _less_ cost per FPGA. Manufacturing largely has a problem where the cost of manufacturing a populated board effectively costs the same no matter how big the board is. In our case, a 16 FPGA board is not going to cost significantly more to manufacture than a 4 FPGA board.

Quote
Lastly, customer hardware failures are mitigated more with many small boards versus one large board. (if you blow a couple FPGAs on your 64x FPGA board what do you do about it?)

Who said 64x board? I said 64 FPGAs in 4u. Thats four 16x boards in 4U.

Quote

My ideas are purely within the confines of the cairnsmore1 product. How to pack as many into a rack as possible. Not a hypothetical new board. (enterpoint has said they may consider additional boards later depending on the success of the cairnsmore1, for now this is what we have to work with).

That said, you have a very good point about card height. Looking again at the mechanical drawings, once you consider motherboard thickness, connector height, and raised MB plate thickness the board likely won't fit in a 3U. (it would be damn close though, 3U is 133MM but internal space will be less, this board is 126.4 so likely won't fit in the end).

But I don't see why you think a "blade server" type approach is inappropriate? It offers high density (at least close to that of a super high-density board) and it offers modularity, easy maintenance (swap boards out), lower risk in the event of failure, and most importantly to many, smooth scalability (easy to keep buying small volumes of boards and expanding rather than having to drop $30K at a time).


Its an unusual design and connectors love to break off of boards. Its not a good idea and it costs money. There is the exact same risk in the even of failure: some of your FPGAs stop working.

Quote

Now considering 4U cases, an ideal option would be something like http://www.newegg.ca/Product/Product.aspx?Item=N82E16811165475
Remove the motherboard mounting plate, and mount the power supply where the 3x 5.25" bays are in the front. That would allow a full case width and a flat mounting surface in the back for the cards. You can easily fit 8 cards wide with plenty of room for heatsinks, and should be able to fit 2 cards deep in that config. This gives the same yield of FPGAs/U that your idea has, but is overall cheaper (1U rackmount cases are more expensive generally. or custom rackmount enclosures are also expensive, meaning per 1U you would be looking at probably $200-$300 per case if you include a power supply, making for $800-$1200 per 4U) in my setup that's $300 for a 4U case, $200 for PSU, so $500 total in case cost per 4U, same total number of FPGA, and I still have room to grow in the front half of the case (could always remove the hotswap drive cage and mount more cards up there, or have room for an added controller for standalone mining or whatever).

I think considering these cards specifically, that type of solution is the best way to go. Too bad it's so close to the 3U spec. If it would fit in a 3U that makes it more dense, which is even better.

Why are you so intent on essentially hacking this up like an idiot? Thats expensive to mass produce, stop that.

Lets try to figure out the total cost of making these the napkin way, and a quad costs $640 to buy.

My way:
per 16 FPGA/1U: $2310 for a 16 FPGA board, $90 for a Norco case that fits EEB and has 5 40mm fans, $50 for a Athena Power 1U 300w PSU
total cost per 4U: $9800 for 64 FPGAs, or $153 per FPGA
if something goes wrong: I lose 16 FPGAs minimum and maximum.


Your way:
Impossible to calculate because you're talking nonsense. What rack mountable case is going to fit 24 inches of cards? And don't say "just make a 8 FPGA 24 inch card" or something. The reason I specifically picked PCI-sized boards is because it is cheaper to produce PCI-sized boards due to the entire industry based around making them.

So, sure, lets use rainbows and unicorns and say you can fit 24 inch cards in cases that are somewhere around 23 to 31 inches deep inside without modifying the case (removing unused drive bays COSTS MONEY, changing the case design at all COSTS MONEY). And each one of those cards costs about, oh, $1220 to produce, and you can fit 7 cards in there, so thats $8540 for 56 FPGAs, plus who knows what for some controller board (lets say $100) because you just really really want one instead of just using SATA plugs like BFL did for the minirig.

per 56 FPGA/4U: $8540 for 7 56 FPGA boards, $100 for a board that does nothing but route serial connections, $70 for a Norco 4U case that fits EEB and has 2 80mm fans (and we need more than that so theres even more money wasted), and $160 for a NZXT Hale 90 750.
total cost per 4U:$8870 or $158 per FPGA.
if something goes wrong: You lose 8 FPGAs minimum, 58 maximum.

So not only do I get more density per 4U, my solution comes in cheaper.
1082  Bitcoin / Hardware / Re: Quad XC6SLX150 Board - Initial Price 400/$640/520 on: May 18, 2012, 02:46:44 PM
Yes you can. Smiley

If you use a motherboard design (with sockets to vertically mount the cards). The new 1.1 rev cards have a high current power connector mounted vertically, and the ribbon connectors for data up/down link from each card, so you can mount the cards vertically plugged into a power distribution backplane, and daisy chain several together using short ribbon jumpers (like crossfire bridges).

Even without the motherboard, you can do this with brackets to hold the cards vertically.

You loose the on-card fan and use push/pull through the case as I suggested.

Vertically the cards are just right to fit on a board in a 3U case. and this way they can be laid side by side to fill an EATX board (2 rows).

And yeah I know not all rackmount support EATX but many do, I've already priced out several with plenty of room. (yeah I know EATX might not have room for 8 cards by 2 rows deep might only be able to do 12 cards, but the cases I'm looking at relocate the PSU to the front of the case, allowing the full 17" wide back half for motherboard. That will easily fit 8 cards, 2" each for plenty of airflow. 2 rows deep.

You're trying to go for a modminer "blade server" kind of design, which isn't entirely appropriate either. Lets try this instead.

Lets say you use a 4U case (3U won't fit full height cards) and used full sized PCI-shaped cards and no backplane at all (power and USB/GPIO (say, using a SATA plug instead like BFL is doing) is on the end of the card like GPUs), and you put 4 FPGAs on the card. The card will have to be 107mm by 312mm (or less: many cases, even rackmount, won't fit a full length card; 6990s and 7970s are full length), so you're fitting the FPGAs in a straight line instead of a quad configuration.

Now, because of the heatsink requirements, you're going to have to fit these in double thick configurations (using, I assume, pure copper 2U northbridge heatsinks and forcing airflow through them from the front of the case), so you're putting around 16 FPGAs in a case (7 case slots, 1 overlaps with the case so it needs a 1 slot bracket)

Now, if you pack these in even harder using 1U northbridge heatsinks, that'd be 4*7, powered using 7 PCI-E 6/8 plugs, or 28 FPGAs in 4U.

Now, my 16 FPGA in a 1U or 2U case? In 2U, thats 32 FPGA per 4U, in 1U, thats 64 FPGA per 4U. I think my idea wins.
1083  Bitcoin / Hardware / Re: Quad XC6SLX150 Board - Initial Price 400/$640/520 on: May 18, 2012, 02:19:32 PM
The board width is almost perfect for a 3U rackmount case though, so with a motherboard/backplane to carry/power them, and the daisy chained comms, you could do the motherboard to EATX standards, and probably fit 16 miners (4 FPGAs each) so total 64x FPGAs to a 3U rackmount case, which would draw in total around 800W so with a decent highend PSU that should work nicely for density. Allowing push/pull airflow past them, decent power density, and easy modular maintenance.

Also leaves the rest of the case (drive bays and so on) to mount a small host system, LCD status displays, or whatever else is needed. (or they could build the host onto the motherboard which would be really ideal). With that kind of setup you could grab a decent rackmount case for $100, a PSU for another $200 so at MOST (including tax/shipping) you're talking $500 per 3U 18board cluster in supporting bits. (I guess that doesn't include the cost of the (so far fictional) motherboard though).

Anyway that's the direction I'm thinking anyway.

Quite a few rackmount cases will fit EATX (330x305), thats 4.18 times more area, so that could theoretically fit 16 FPGAs (assuming ATX fit 12), and it'll draw about 200 watts (assuming 4x Spartan 6 uses 50 watts with the new ~250 mhash bitstreams). You can't just fit 4x existing boards in manually because you can't fit 376x252 inside of 330x305 (and EATX is pretty cramped inside cases as it is), so they'll have to place stuff differently on a new board.
1084  Bitcoin / Hardware / Re: Quad XC6SLX150 Board - Initial Price 400/$640/520 on: May 18, 2012, 12:38:47 PM
I couldn't easily find this, but what are the dimensions of the board?

Since I know I wasn't the only one curious about it's dimensions.
Yohan confirmed these details via email when I ordered.

"Board is 126.492mm x 188mm give or take manufacturing tolerance. Main
mounting holes are 5mm (x) and 5mm (y) in from the corners."

Huh, thats actually bigger than miniITX which is 170x170. ATX is 305x244, which could probably fit 12 FPGAs with room to spare.

Maybe one of the manufs will start making 12 FPGA boards with the four outer mount holes fit for ATX cases and power itself off a P4 (16a 12v) or EPS12v (28a 12v) plug?
1085  Economy / Securities / Re: [GLBSE] Diablo Mining Company (DMC) on: May 18, 2012, 02:15:53 AM
Seems like a lot of people had the same idea as me:

Buy 2 shares of X for 0.6 BTC, trade them for 1 share of DMC and sell them for slightly less than 1 BTC...

I'm not really sure if you can keep up this model much longer without seriously hurting your IPO income.

I'm not sure this was intended to happen, but it certainly has. If he sells all 200k shares, percentage-wise, the impact is still small, but I agree, this can do naught but dilute the value of DMC shares.

I really doubt I can exchange all 200k shares this way. However, if someone wants to try, they are more than welcome.

I meant that if the rest of the shares are bought @ 1 BTC each, the effect of what bond exchanges have happened on DMC's assets would be negligible. Not enough bonds exist right now, so even if someone wanted to buy the remaining shares with bonds, they wouldn't be able to.

There isn't enough bonds, but I think the larger bonds are growing to accommodate my plans. YABMC just launched a huge expansion project, for example.
1086  Economy / Securities / Re: [GLBSE] Diablo Mining Company (DMC) on: May 17, 2012, 11:36:01 PM
Seems like a lot of people had the same idea as me:

Buy 2 shares of X for 0.6 BTC, trade them for 1 share of DMC and sell them for slightly less than 1 BTC...

I'm not really sure if you can keep up this model much longer without seriously hurting your IPO income.

I'm not sure this was intended to happen, but it certainly has. If he sells all 200k shares, percentage-wise, the impact is still small, but I agree, this can do naught but dilute the value of DMC shares.

I really doubt I can exchange all 200k shares this way. However, if someone wants to try, they are more than welcome.
1087  Economy / Securities / Re: [GLBSE] Diablo Mining Company (DMC) on: May 17, 2012, 11:34:43 PM
Seems like a lot of people had the same idea as me:

Buy 2 shares of X for 0.6 BTC, trade them for 1 share of DMC and sell them for slightly less than 1 BTC...

I'm not really sure if you can keep up this model much longer without seriously hurting your IPO income.

I've recently answered this for someone else, so I might as well repeat it here.

Some people are viewing this premium as strictly "buy DMC for 2/3rds the cost", which is not entirely true. Up front, yes, you buy the DMC shares for that, but you give up two short term abilities: dividends (they are cut in half as per the 50% dividend/50% growth agreement in the contract), and the ability to sell (there is not a huge demand for DMC shares yet as the company is still new). If you factor in all the "lost" dividends until DMC dividends increase past what you would have originally gotten from the original bonds, it evens out in the short term.

Also, there is this other issue where if they keep buying shares to sell to me, the effective premium I paid/pay on past/future shares goes down because value increase. Not that I'm complaining, mind you, it'd help everybody in the Bitcoin world if bond prices started rising.

Still, theres a fair bit to go on that. If people want to go buy 1000 shares of something right now and trade me, it might not effect some of the bonds too much and still be worth it for them and still worth it for me.
1088  Bitcoin / Mining / Re: Orphan Blocks on: May 17, 2012, 10:37:23 PM
I have been mining on ecoinpool a private pool now for two months.  I have found 2 different BTC blocks and both blocks show as orphaned and nothing to show for my work.  Any ideas why I am getting orphan blocks?  How do I fix this problem?  Instead of mining earning nothing I think I am better off mining a regular pool since I have no payouts with 2 blocks found.

Sounds like the version of Bitcoin ecoinpool is running is dangerously out of date.
1089  Economy / Securities / Re: [GLBSE] Diablo Mining Company (DMC) on: May 17, 2012, 06:24:25 PM
Wow, DMC is really taking off here.

We've passed the 1000 share mark, and we're not slowing down.

Also, I want to mention this so it doesn't get lost in the shuffle: someone traded exactly 666 shares of BMMO in. I love it when people totally get me.

https://bitcointalk.org/index.php?topic=77469.msg901464#msg901464 is acting as a live tally on the asset trade. I'm not going to leave this window open forever. Once Bitcoinica's destruction stops effectively halting GLBSE and everything is flowing the way it should again, the window gets closed and everyone has to buy shares the more expensive way.

Don't wait, act now, orders in the next 20 minutes get free S&H, etc etc. You know the drill.
1090  Bitcoin / Hardware / Re: Quad XC6SLX150 Board - Initial Price 400/$640/520 on: May 17, 2012, 02:11:14 PM
Hey Yohan,

I know this may sound like a strange question, but is there any mass produced case that would fit the quad board? It looks to be roughly the same size as a PC104 board, but I doubt any of the mounting holes match.
1091  Bitcoin / Bitcoin Discussion / Re: [Emergency ANN] Bitcoinica site is taken offline for security investigation on: May 17, 2012, 07:59:43 AM
Who needs a hot wallet to begin with?

They don't. That's why anything in the future will likely use ZipConf instead.

So THATS what ZipConf is. Okay.
1092  Bitcoin / Bitcoin Discussion / Re: [Emergency ANN] Bitcoinica site is taken offline for security investigation on: May 17, 2012, 07:45:50 AM
Who needs a hot wallet to begin with?

The point I am trying to make is, is it really that bad (from a customer service perspective) if withdrawals aren't immediate?  Why do the withdrawals have to come from the platform in the first place?  Ideally, the platform should not have any private keys on it whatsoever.

For example, mtgox makes several thousand transactions a day. I wouldn't want to manually handle that.
1093  Economy / Securities / Re: [GLBSE] Diablo Mining Company (DMC) on: May 17, 2012, 04:07:21 AM
By popular request, I've added TYGRR and TYGRRMBA
1094  Bitcoin / Bitcoin Discussion / Re: [Emergency ANN] Bitcoinica site is taken offline for security investigation on: May 17, 2012, 02:51:16 AM
How about just ... Not keeping bitcoins on the server?

How bad would it be if all non-trivial withdraws needed up to 24h to be done manually?  Where the platform issued pgp signed and encrypted withdrawal requests that were reviewed and performed manually, offsite?

Well, with any site that needs to send bitcoins back out you need whats known as a hot wallet, ie, a wallet that ONLY has enough to do day to day business... you setup your software to send excess coins to a cold wallet (offline or otherwise hidden on another machine), and message you if you need to manually transfer from cold to hot.

No one has $90k worth of coins in their hot wallet.
1095  Bitcoin / Hardware / Re: Quad XC6SLX150 Board - Initial Price 400/$640/520 on: May 17, 2012, 01:46:46 AM
Don't know how much the price difference is in the UK, but you might want to consider using this fan:

http://www.silenx.com/quiet.fans.asp?sku=efx-12-15

More quiet, good air flow and fairly cheap. This one is thanks for Fizzisist for making me a fan (pun intended)!

Its not a Delta AFB1212. There is no reason to EVER use non-enterprise/industrial fans in a computer.

http://www.delta.com.tw/product/cp/dcfans/download/pdf/AFB/AFB120x120x38mm.pdf

They make ones that are slower/quieter than what most people are used to from Delta (although, if you're worried about noise, taking a faster than and undervolting to 5v is often superior, as is ramping voltage on chip temp; it also reduces wear greatly).
1096  Bitcoin / Bitcoin Discussion / Re: [Emergency ANN] Bitcoinica site is taken offline for security investigation on: May 17, 2012, 01:44:20 AM
...
Kids, here is how you secure a financial server:
...

Here's another couple of ideas:

1) Don't follow anyone's cookie-cutter solutions...particularly if they are good ones (because if they are, they will be popular.)

2) If you are serious about security, don't advertise your genius ideas.



No, virtually every secure server uses those concepts.

This is what I do: I disable root login locally AND through ssh (local root disable is borderline security through obscurity though, you have to know the l/p of people who can su before you can cause any real damage), and I disable ssh login with passwords (key only), and I also use keys with passphrases only (so even if they steal the key from me physically, they can't use it).

Installing a firewall (ie, a handful of iptables rules) is somewhat overkill, you should only be running software that can be told to listen on specific IPs (ie, listen locally only). iptables kills network performance, so only use it if you must.

Running the actual httpd/db/maild/etc on a vm that itself is stored on an encrypted image is rather popular. You can boot the machine and do basic maintenance on the VM (ie, back up everything), but you can't start it or read the image unless you have the passphrase. Its basically a ghetto way of doing LOM cheaply, especially if your VM has its own IP and the host isn't masquerading for the VM.

Bare metal over VPS only stops one single attack: host reading VM memory. Which, for financial things, is worth it for some people.

Having your own hardware coloed instead of leasing a dedi is not going to increase security: others still have causal physical access to your rack, so you'll need to rent your own locked cage if you want to take paranoia the whole 9 yards.
1097  Economy / Securities / Re: [GLBSE] Diablo Mining Company (DMC) on: May 16, 2012, 05:38:26 PM
Ive added ABM to the swap list.
1098  Bitcoin / Hardware / Re: [ANN] ShaLab on: May 16, 2012, 03:40:00 PM
scam

You keep using that word. I do not think it means what you think it means.
1099  Economy / Securities / Re: [GLBSE] Diablo Mining Company (DMC) on: May 16, 2012, 02:33:16 AM
Due to popular request I've added FPGA.Contract and YABMC for the trade offer.
1100  Bitcoin / Hardware / Re: CAIRNSMORE1 DUAL AND SINGLE VERSIONS on: May 15, 2012, 09:49:49 PM
This is one big difference that you will find with FPGAs and a big advantage over GPUs especially when loading isn't constant for whatever reason. A XC6SLX150 FPGA can run from a few hundred mA when an easy design is loaded or throughput is reduced. The actual current depends highly on the clocking rates and the design loaded. From what I have seen the best GPUs still take about half the power when lightly loaded.

We selected 12A capability given what other boards seem to use i.e. 8-10A. Runnning in the 8-10A zone also works with our regulator choice and it is in a better efficiency band than when running at 12A.

In the unlikely occurance of a fault our sectioned power also allows a faulty section to be turned off and also limits damage should a short occur. It would be much worse if we had a single 48A supply and that got shorted also taking down the whole board at the same time. 48A tends to vapourise tracks and do significant damage to anything on the current path.

Yohan

A lot of people are requesting this feature, and I hope you think about this for future products: use programmable VRMs. A lot of people want to undervolt their FPGAs to increase efficiency at the end of their effective mining lives and it would increase sales over the BFL juggernaut.
Pages: « 1 ... 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 [55] 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 ... 118 »
Sponsored by , a Bitcoin-accepting VPN.
Powered by MySQL Powered by PHP Powered by SMF 1.1.19 | SMF © 2006-2009, Simple Machines Valid XHTML 1.0! Valid CSS!