True, but the chain can only be 5 hubs long.
So if you have 20 5port hubs, connect one to the pc, then connect 5 of them to the first one, then connect the last 16 to the 5.

The chance to find a share in the 11->11.3 seconds range is the same as find one in the 0->0.3 or 5.5->5.8 or anywhere for 0.3 seconds.


I think people are talking about different meanings for the term efficiency.
There is an efficiency where you want to find as many shares possible per jobs. You want to set the interval large enough so the job is completed in that time.
There is an efficiency where you want to find as many shares possible per time. You want the FPGA have new work before it completes the current job.

If you set the interval between jobs to low the first one drops, thats a higher load for the pool.
If you set the interval between jobs to high the second one drops, the FPGA has nothing to do.

If I had a FPGA miner I would try to set the interval to the time it takes to complete a job minus the maximum time it takes to get a new job.
That way I know the FPGA has new work to do on time and the pool don't get to high load.

But, I don't have any real world experience, so I can ofcourse be wrong somewhere. It's just my software engeneer point of view

Type B has 2 usb ports, type A only one.
The dubble usb port count is also worth something

https://en.bitcoin.it/wiki/Mining_hardware_comparison
So the 6970 gets 397 MH/s with 683 GFLOPS, or 1.72 GFLOPS / MH/s
So the raspberry pi GPU gets 24 / 1.72 = little under 14 MH/s
14 MH/s for $25 (A type is cheaper but with the same GPU) is $0.56 / MH/s

Conclusion, the normal GPUs for a normal pc are 3 to 6 times more efficient.

Another point, (most? all?) GPU miners are probably written with the opencl library, I don't know if there exists a version of it for the raspberry pi.

RASPBERRY-PI - RASPBRRY-CHIPSET - CHIPSET, RASPBERRY PI, MODEL B - £21.60 (google tells me thats € 25.54)
RASPBERRY-PI - RASPBRRY-PCBA - SBC, RASPBERRY PI, MODEL B - € 33,02

What I think (but can't find clear on the website) is the first one is the components (chipset) and the second is the complete assembled version.
The first one is listed under accessories, the second one under primary platform.

/edit, seems I can't order them yet.
Binnenkort verkrijgbaar - registreer hier uw interesse (Coming soon - register your interest here) at farnell site.
Register here to express an interest in Raspberry Pi at rs site.

Unless the input/output is buffered before sent to the sha256 engine.
In that case it doesn't matter how often you send new work.

Many are different, but exchangeable.
If you look at http://nl.wikipedia.org/wiki/Netstekker type e for belgium and type f for the netherlands, many connectors in the netherlands have an extra hole so they fit in the wall in belgium.

Or a SheevaPlug.
Are the Raspberry Pi computers on stock?

If you have 100 devices on 1 usb port, you definitely make use of usbhubs.
If you have a root hub with 5 ports with each 5 another 5 port hub and on those each a 4 port hub you have a totel of 5*5*4 = 100 ports.
You can just unplug 1 of the 5 hubs on the root hub and see if 24 more or 25 more devices fail. If 24 more fail you found the hub with the broken device.
A lot faster than trying each of the 100

What do you want to know about it?
It's not a FPGA and if it is possible to mine on it, it would be very slow and no networksupport on it.
Maybe a normal pc can mine faster in just the time it takes to talk to this thing.

Small calculation,
4 days * 24 hours/day * 6 blocks/hour = 576 blocks per 4 days.
41/576 blocks = 7.12% of total hashing power of the network.
Impressive :-)

What does the "relayed by" mean anyway?
Isn't it just the node in the bitcoin p2p network who was the first who told blockchain about the new block when discovered?

Any big pool ip disappeared? might be a changed ip address.

You can also try http://www.verzamelaarsmarkt.nl/nl/bankbiljetten/Nederland_100_Gulden_1970_/1/15/121.aspx
If it qualifies for quality Zf (obvious used with multiple folds both horizontal and vertical) they sell it for 125 euro.
If they buy it for half that value (i have no idea how much they will offer) you get 62,50 euro each.
You can try email them at the verkoop@ address found at that site.

C:\Users\User Name\AppData\Roaming\Bitcoin\wallet.dat
If you replace it with your old wallet.dat it would probably work

The first part I have no idea.

The second part, all transactions are in the blocks in the network so it's easy to keep track of everything.
Just throw it in a database and ask the database what you want to know.
Why should it be hard to search?

I don't understand.
If the h value of the midstate is 0x5be0cd19, then the next h value that is added to it must be exactly 0xa41f32e7 to get the 0x00000000 value to make a valid share at difficulty 1.
Isn't that a way bigger advantage? Now you know for sure you got a value you want and not some strange percentage.
I assume no pools use shares less than difficulty 1 and for mining in pools with difficulty greater than 1 it should be easy for the miner software on the host computer to check if the share with difficulty 1 is also valid for the pool with difficulty x.

When the total network hashing power get higher you get less BTC for your shares.
So if the BTC stays at the same price but the network speed gets 10 times as fast, and normally you need 10% of your BTC to pay the bills for the electricity, you now need all of your BTC to pay for electricity.
FPGA's are about 10 times as cheap in electricity consuming so they will rise from 1% of your BTC to 10% of your BTC.

I do think so.
This is what I base my answer on,
So if the rs232 is at 115k2 you waste 512 / 115200 of a second, 4.444444ms which is at 200MH/s a total of 888,889 hashes each time you send new work.

For easier example I change 512bit to 32bit

FPGA buffer starts at some value 0x??

New value is 0x12345678

Computer sends a byte 0x12
FPGA buffer is now 0x???12
Computer sends a byte 0x34
FPGA buffer is now 0x????1234
Computer sends a byte 0x56
FPGA buffer is now 0x??123456
Computer sends a byte 0x78
FPGA buffer is now 0x12345678

New value is 0x87654321

Computer sends a byte 0x87
FPGA buffer is now 0x34567887
Computer sends a byte 0x65 but FPGA doesn't receive
FPGA buffer is still 0x34567887
Computer sends a byte 0x43
FPGA buffer is now 0x56788743
Computer sends a byte 0x21
FPGA buffer is now 0x78874321

FPGA calculates with wrong value

New value is 0xCAFEBABE

Computer sends a byte 0xCA
FPGA buffer is now 0x874321CA
Computer sends a byte 0xFE but FPGA doesn't receive
FPGA buffer is still 0x4321CAFE
Computer sends a byte 0xBA
FPGA buffer is now 0x21CAFEBA
Computer sends a byte 0xBE
FPGA buffer is now 0xCAFEBABE

FPGA calculates with correct value