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Interesting. Assuming your design can be ported from the Cyclone IV to the Stratix III, an EP3SL200 at 213MHz with 250 of your 800-LE cores would produce 416 Mhash/s. That would account exactly for the performance of the BitForce Single (rumored to be two EP3SL200 chips = 832 Mhash/s)...
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I want to sell a a bunch of HD 6990 cards. I will give preference to those buying in bulk. Price for each (USD or equivalent in Bitcoins):
$510 for qty 1
$490 for qty 2-3
$470 for qty 4-6
$450 for qty 7+
They have all been purchased after April 2011, and all have 1 or more years of remaining warranty time. I kept the sales receipts, and original packing & accessories:
Sapphire: 2-year warranty
PowerColor: 2-year warranty
MSI: 3-year warranty
Visiontek: lifetime warranty
I have used them for mining in a very clean datacenter-like environment (filtered air, cool temperature). I have a decent reputation (check signature). I can either ship from Los Angeles, or you can pick them up locally.
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There are clearly people purposefully sending invalid P2SH transactions on the network, and this is causing some miners who failed to upgrade to waste resources mining on top of invalid blocks. This in turns caused the network to lose about 1-2 Th/s since April 1st: (graph captured from http://bitcoin.sipa.be)  |
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And you still have to cover your cost. How much cost the ASIC? The bunker? The maintenance? The electricity (even if its supposed to be cheap, 5 THash will still cost a good chunk of electricity)?
5Th/s would only costs $1825/month in electricity. This is peanuts compared to the $0.5 million NRE cost of developing an ASIC. (That's assuming ASICs capable of 200 Mh/J, or an order of magnitude better than FPGAs, and an average rate of $0.10/kWh.) |
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Lastly, there is the issue of resale/reuse value. I think everyone agrees that the BFL Single is a bitcoin only box at the moment. Icarus could possibly be used as a dev board(people tout Icarus' IO pin count). I have no clue on ZTEX and it sounds like X6500 has a very low IO pin count.
Ztex is the most general-purpose board, and the easiest to develop for. The company has been around for at least 3 years and publishes an SDK for their various FPGA boards: http://www.ztex.de/firmware-kit/ And their products have a 2-year warranty. IMHO, if you care about resale/reuse value, Ztex is the way to go. I do agree that, in small quantity, Ztex products are expensive. So, buy in bulk  |
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I don't have any way to scan it, but remember that QR codes have an ECC error correcting algorithm built in. It may still be possible to read the code even if it has been edited slightly.
Nope. I just tried with my phone. |
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You didn't notice the little QR code thingy...? What a lot of work to reverse engineer the address from the date and the amount.  lulz hahahahaha well everyone cant be leet hax0rs like you RJK  What kind of leet hax0rs are you guys, if you couldn't spot that the QR code was obfuscated, with your naked eye? "lulz" indeed   |
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I have caught blockexplorer.com not upgrading to a Bitcoin 0.6.0. As a result it is seeing lots of chain reorgs since April 1st (I contacted Theymos already - he is going to upgrade tomorrow): http://blockexplorer.com/q/reorglogI am curious in anybody else is seeing side effects caused by P2SH since April 1st? |
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Just ordered another single with bitcoins ... looks like they're using bit-pay now  The blanked Bitcoin address is 1jyAQDoog4F4UFDt8nQCc2bTDGKcWydXdPeople, you can't expect to protect your addresses if you talk about the amount of BTC that was involved in the transaction, and/or if you give the time of the transaction. Remember that the blockchain is public... |
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Let's give BFL a shot.
Ordered: 2012-03-27
Shipped: TBD
Qty: 10
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Altera always have been a little bit expensive than Xillinx, so Artix7 200k may be with same or little lower price. This is gona be madness Artix 7 should be cheaper than Cyclone V, because Xilinx claims Artix 7 matches its predecessor's performance (Spartan 6) but sells at "35% its cost and is twice more energy efficient" (can't remember where I obtained this info, I just jotted it down a while back). That said, please do keep us informed about performance numbers you may achieve... |
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You forget that the 80 Plus standard does not guarantee efficiency below 20% load. Which is why I criticize idle measurements at the wall so much as they are likely to be below 20% load.
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Here is a fictitious system in idle/load conditions demonstrating my point that cards can draw more than what the kill-a-watt difference shows:
Idle: 130W at the wall, power supply outputs 95W (73% efficient) = 15W to the video card + 80W to the rest of the system
Load: 200W at the wall, power supply outputs 176W (88% efficient) = 96W to the video card + 80W to the rest of the system
yochdog would conclude from the kill-a-watt readings that the card under load is drawing at most an extra 70W (200-130), but in fact, it is drawing an extra 81W (96-15). This is why subtracting the idle from the load wattage at the wall is not as accurate as you all seem to think.
At the very least, if a kill-a-watt is all you have, I suggest you:
- publish your power supply specs to look up the energy efficiency curve at different loads
- measure "idle" condition with the card physically removed from the system
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I disagree for exactly the same reasons.
2.62 Mh/J is meaningless as it's not comparing like-for-like, you're adding in the unknown variable of the system, which will be vastly different (as you noted) system to system.
3.74 Mh/J is meaningful, as other people, who wish to compare their values, can use this number by factoring out their own baseline system power.
Your argument is invalid because 3.74 Mh/J is also influenced by unknown variables, such as the efficiency of power supplies which varies with load: http://www.anandtech.com/show/2624/3Here is a thought experiment: yochdog's load/idle power draw is 512/154 Watt. He replaces his power supply with one that is just as efficient at high loads, but more efficient at low loads, changing his measuremnts to 512/130 Watt. Suddenly his mining efficiency went down from 1340/(512-154) = 3.74 Mh/J to 1340/(512-130) = 3.51 Mh/J ! Explain to me why using a formula in which efficiency becomes worse when using better hardware components is useful? Of course, if everybody had clamp meters, the ultimate way to measure the efficiency of a card would be to measure current at the PCIe power connectors and PCIe slot, like I demonstrated a while ago: http://blog.zorinaq.com/?e=42 |
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Let me correct: - 3.74 Mh/J is meaningless to us, because it is inflated by your inefficient baseline idle power of 150W (perhaps you have a high-power CPU, or your PSU's efficiency sharply drops at low loads, or you are running a graphics-intensive Windows Aero desktop, etc)
- 2.62 Mh/J is meaningful.
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All I am trying to measure is the additional power consumption of the cards. This is a machine that is always on, and has been always on for the last 3 years. Thus, the idle power consumption is the baseline, as it would be consuming that regardless. Determining the incremental energy consumption is all I am concerned about, and now have a good approximation of that number.
Now if I was building a dedicated mining rig from the ground up, of course the over-all system wattage would be the important number.
And this is precisely my point! This makes your numbers meaningful only to you, and meaningless to all of us on the forum (because most people here favor more efficient systems -- and a dedicated 2 x 7970 miner idles at 90W or so). You should have disclosed your unusually high baseline idle load in your first post. |
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Alright, I went and re-measured the numbers. I think what happened was I screwed up the idle wattage the first time around. Here are the correct numbers:
System idle: 154
Mining with above settings: 512
Hash rate: 1340 MH/s
Soooo, I am getting 3.74 MH/watt.
No. It is nonsense to compute the efficiency as 1340/(512-154) = 3.74 Mh/J... For example, if the cards' idle power consumption would be worse and would be making the machine idle at 350 Watt, would you conclude it would raise efficiency to 1340/(512-350) = 8.27 Mh/J ? Of course not! You are in fact getting 1340/512 = 2.62 Mh/J which is in line with what I have measured on my own HD 7970 machines. |
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I was wondering, if governments wanted to attack BitCoin, then all they needed was enough money to fund 51% Processing Power project?
If so, how much would it cost them to construct this huge farm using a) GPUs b) FPGA and c) ASICs? Anyone has any figures?
It would take about 15000 BFL singles to surpass the processing power of the current network (about 12 Th/s), or $9M if you can manufacture 15000 units at your current prices :-) It would fit a medium-sized datacenter if you can go relatively high with power density: 120 racks of 10kW each, with about 120 singles in each rack. |
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I am sure he means device, not chip. Four Spartan XC6SLX150 (eg. two X6500 miners) will do 800 Mh/s at ~33 Watt. Plus Raspberry Pi = 40 Watt.
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