[Are there any open source pool hoppers out there that are actually using longpoll to assist in block completion estimation or are they all just scraping APIs and web pages for block completion times]

I became interested in bitcoin mining, mining pools and the bitcoin network last week so please excuse the fresh smell.

After reading the initial Satoshi paper and seeing how the implementation has evolved and differed from the original (and brilliant) design I started to consider the 'dangers' of large bitcoin mining pools.  It seems that if a determined attacker was able to compromise just two machines they could compromise the entire bitcoin network[2].. scary stuff for anyone with an investment in bitcoin no?  Defeats the purpose of a non centralized trust model too doesn't it? Anyway...

I decided to fire up wireshark on a couple of my mining rigs and set up filters to grab interesting bitcoin related traffic.  Using pylibpcap and massaging the data shows interesting statistical information (long poll data), server response time changes(as workers all find out that they need need data), and changes in the data value in the RPC request seem to correlate nicely and filtering out the noise gets easier with a larger number of miners.

Question:
Are there any open source pool hoppers out there that are actually using longpoll to assist in block completion estimation or are they all just scraping APIs and web pages for block completion times?

[1] http://www.bitcoin.org/bitcoin.pdf
[2] *...by gaining the majority of the bitcoin C/GPU vote The pool administrators are active and easily contacted.  An attacker with an adobe/java/office 0day could potentially social engineer their way into compromising pool operator personal machines and hop the fence from there.  Operators could be coerced. Operators could be malicious.

I took an interest in bitcoin last week and started reading as much as I could.  I love the idea from a philosophical and technology perspective and I am eager to see the community thrive (especially my small investment in a mining rig heh).

My question is meant to highlight a possible weak point in the integrity of the bitcoin network OR clear a misconception from my mind about the propagtion of trusted blocks and the trust modle of the P2P network.

QUESTION:
Since 'mining' pools such as BTCGuild and deebbit were not considered in the design of the trust model and distribution of work, would it not be possible to hijack the blockchain by compromising the top n pools?  If an attacker was able to gain 51+ % of the bitcoin network for a 10min period (the defined time for propagation of blocks through the network) they would be able to supress a legitimate transaction and have it invalidated/stomped out.

[1] According to this graph: http://bitcoin.sipa.be/speed-ever.png the total computational capacity of the bitcoin  network is just over 10G Hash. (*Note this number needs to be verified -- it seems low and the points on the graph grow dont grow linearly -- could be much higher than 10GHash but no higher than 50.  Clarification on this point would be nice is anyone has a better number)

[2]
Deepbit pool rate: 5320 Gh/s
BTC Guild pool rate: 2340.95 GH/s

If an attacker was able to compromise the TWO bitcoin work distribution servers at BTCGuild and then one at deepbit (I realize thee are probably load balanced but the compromise could be of DNS servers (social engineering?), or even a local attack at a data center (if you're a particular nation state that is against bitcoin for example).

The question summed up: Is 7600GH/s enough to disrupt the bitcoin network and if so is there a method of preventing this if pools continue to be such a significant portion of the vote?

I just noticed that newegg is having a 'special' on the XFX 6870 for $184.99 with the following promo code:  CEMCKCHC23

It was emailed to me directly so it may not work for you or it may only work once.

The mining guide says 190 so this isnt a huge dead but I wanted to post the promo code just in case.
6870    $190    Easy    278.31 (hashrate)

[bad luck]

Hey so I've noticed that there are two stats associated with speed for a given worker.  On the client there is a consistent MHash rate and another one in brackets. 

Assumption:
I assume (dangerous I know) that the steady number (the first one) is the actual hash rate of the card.  This is the speed at which hashes are being generated.
The second one looks to be an 'effective' speed and is directly affected by the luck you have generating shares... sometimes you can have bad luck¹ and your effective MHash rate is lower than your actual hash rate.  Is this a correct assumption?

Question:
*If that is the correct assumption then I've observed some odd behavior (that could quite possibly be simply related to bad luck and impatience) it looks like my effective hash rate is ~10% less after a 24hr run.  This wouldn't surprise me at all if my actual hash rate was slowly as well.  I'd probably just remedy that with a schedule task to restart the miner jobs.


¹ - Bad luck means you're generating less valid hashes than average for your given hashrate and block difficulty.

Invitations:
Tear me a new one if I'm off on this.  Nit pick all you like... curse, swear, call me names... just include a correction as well

Im looking for recommendations for cheap mother boards that will support three cards... something in stock at newegg

Since this is the only place I can post right now it's going to sit here in the newb form.  If a moderator sees fit to move it that's great

I wanted to draft a quick post to document my experience setting up two XFX 6850s purchased from tigerdirect (this seems to be important-others having the issue also purchased from TD).  Some people have had success overclocking the cards using Trixx or MSI AB (After doing the UnofficialEULA change to the CFG file) and others seem to be completely stuck.

It turns out that these cards come in multiple flavors and that they changed voltage regulators.  Currently, MSI AB and Trixx are unable either unable to see the registers in BIOS to adjust voltage (via adjusting the duty cycle) or unable to control them.

There has been a lot of noise surrounding the issue and filtering out the typical OC issues (not doing proper eula cfg mods, proper catalyst drivers, non-conflicting utilites (disable CCC), etc) has been difficult.  If anyone else has this card and wouldn't mind taking a high res picture of the PCB I would really appreciate it.  Please let me know if you've had success increasing the voltage and if so with which utility.

Cheers,
dyn