yeah, it has always been that way
and you always tell people, they shouldn't invest into new rigs,
yet those that do made profit and probably already paid off their new rigs.

very strange that mining for me has always been like "assuming difficulty rises, but price doesnt, it might become non-profitable in about 3months",
it was like that in october, when i bought my first ATI card, it was exactly the same when i bought the second card in december,
it was still the same when i bought 2 other cards in february and again 2 cards about 2-3weeks ago, everytime i had at least 3month in profit assuming the price doesnt rise at all.

and guess what?
today that same (pessimistic) calculation tells me, that mining might become non-profitable around september,
so the risk to take isn't any bigger than it was half a year ago.

but we all know why you tell everyone not to invest in rigs.  

why do you predict the difficulty to continually rise, if the price doesnt change at all?
the price will change.

i won't and can't predict the future,
i just don't know, what the difficulty will be in 10, or 20, or 30 days
and i also don't know, what the price will be in 10, or 20, or 30 days, maybe it's more, maybe less than today.

it is profitable now and the last year has shown, that price and difficulty will catch up on eachother,
right now, the price leads the way, and difficulty follows, it might be the other way around in 2weeks.

it's always the same with every single difficulty jump,
everytime people start complaining that mining isnt profitable anymore,
fact is, it's more profitable today (at a higher difficulty), than it was a few weeks ago (at lower difficulty) due to the fact, that the price is so incredible high.

let it be a bit less profitable next week, or next month,
i won't care, less profit is still profit.

naja, um zu sehen, ob ein ORcode schon "verbraucht" ist oder nicht, brauchste dann wieder irgendein device, das den code auch lesen kann und ne internet-verbindung, um die blockchain zu durchsuchen.

mit rubbelkarten ist das schon einfacher, da sieht man auf den ersten blick, ob die schon benutzt wurde,
wenns feldchen freigerubbelt ist, nimmt man die karte besser nich an. 
 

in gewisser weise gibts die von die gewünschte Smartcard-Version schon, kuck ma hier.
gut, man kann sie nicht wieder aufladen, wenn sie einmal "verbraucht" wurden, aber mit nem chip auf der karte wäre auch das möglich,
es muss nur irgendwer die dinger produzieren, vielleicht du?  

aber neben den karten-versionen gibts natürlich noch andere varianten, schlüssel internet-unabhängig auszutauschen,
ob auf rubbelkarten, wie hier, oder hier,
oder per QR codes, die man auch auf verschiedenste art und weise verteilen kann, von handy zu handy via kamera und display, oder gedruckt auf papier zum wieder-einscannen.

möglichkeiten sind viele da, musst dir nur was passendes aussuchen.

dish should get some manners,
calling [Tycho] a cheater without any evidence is pretty rude.

why does it matter when he pays out?
he takes a risk by paying you for blocks that aren't mature yet and you pay him 3-10% to take that risk.
he shows ALL blocks found by his pool, so stating he NEVER , again i say NEVER showed which blocks, his pooled solved is simply untrue.

being mad or jealous at someone is no excuse for those manners.

to answer the initial question: yes, it is.

let's say you only get 2x5850 (not 5870s) for $800,
2 5850s get around 700MHash/s and the rig will need ~375W (probably less, but let's just be sure),
at (very expensive) $0.3 per kW/h you'll pay $2.7 per day
at current difficulty the expected average output is 2.88BTC per day,
at current market rates (of roughly $6.5) that's $18.72 per day.

$18.72 - $2.7 == $16.02 per day
16 / 800 == 2% ROI per day

show me an investment opportunity that pays you 2% per day and i'll join it.

you answered your own question,
even passing, that's why, difficulty tries to catch up to the price.

hey there,

is there any way to hide particular forums from my view?

take the russian forum for example,
i really don't care about those, yet can't hide them in any way.
they just make the list of unread posts longer and longer and the worst thing is, that, even when i go to the russian forums and mark them all read, they still show up in the unread posts, as if i never marked them (or maybe there is a hidden russian forum, that i can't mark at all?).

wouldn't 500$ be better? or what about 1000$?

from now on, let's all sell our coins for at least 10000$,
whoever sells below that, will be stoned to death.

it's an error (and this is a lie, but you asked for it)

well, actually BTC would fall under the or something category, so you don't choose it over any of those, it IS one of those.

what if i don't own any USD or CAD or AUD or gold, but BTC? (actually, the only USD i currently have are on MtGox, never had any CAD or AUD or gold, ever)
don't want me as your customer? fine, i'll find another seller who wants my BTC then.

some (that 5850+5970 setup just one of my rigs, i got a few more),
you can expect 350++Mhash/s on each of your 5870s, so it's 1.4++Ghash/s on 4 of them

depends on OS, driver/SDK version, and not at least you preferences

both 
actually on my own pool, but i'm the only one using it so far.

i never experienced any improvement in mining speed when lowering memory-clocks,
the reason i do it anyway is simply, that it
a) needs less power and
b) creates less heat
there's no reason not to lower memory-clocks.

PSU of course, check its specs to see how much power can be drawn on its 12V rail(s).

as mentioned, for a 2x5870 (<400W) rig a 650W PSU should do fine,
i'm running 1x5850 (~150W) + 1x5970 (~300W) on 650W 24/7 for a few months now without any problems.

CPUs: AMD Sempron 140 (probably the cheapest available CPU) will do fine
MBO: no PCIe x16 needed for mining, x8 works too. OnBoard GPU is useless, connect monitor to one of your 5870s
PSU: for dual-5870 650W will be more than enough, 12V-rail has to handle enough load though (calculate ~200W per GPU and you're good).

of course not.
the easiest way would be, to find someone who has bitcoins, and wants whatever you have to offer, may it be goods, services, or another currency.

i don't get your point, speeder,
on one hand you complain about miners selling, and not hoarding coins (i think it's the first time i ever heard that, usually people complain about hoarders),
on the other side, you want all newcomers to only use coins.

how do you expect those newcomers to get coins, if miners don't sell them?
i guess you want them to buy coins from YOU, for a higher price of course, because the supply is smaller due to all other miners hoarding.


my 2 bitcents on the topic:
there is no problem to fix.

nö, keine FPGAs,
die rechnung bezog sich auf mein "altes" setup (ich hab heute noch 2 karten dazugepackt, die letzten, versprochen ), bestehend aus
1xHD5570
3xHD5850
1xHD5970

ein wenig übertaktet sind sie alle, aber nur soweit, wies das jeweilige BIOS, die stabilität bei standard vcore und nicht zuletzt meine ohren zulassen.

alles zusammen verbraucht etwa 1kW und benötigt ~110stunden für einen block,
0.2125€/kWh * 110std = 23.375€uro / 50coins == 0.4675€/coin.

edit:
sorry, sind natürlich nicht 0.2125cent, sondern 21.25cent, oder 0.2125€uro 

nicht so sinnvoll? im vergleich zu was?

wenn du meinst, ein umzug nach spanien, tschechien, oder rumänien sei sinnvoller, bitte, keiner hält dich auf.  
die stromkosten sind jedenfalls weit (weit, weit, sehr weit) von dem entfernt, was an gewinn erwitschaftet werden kann,
vorrausgesetzt natürlich, man benutzt effiziente hardware (ati-karten).
die tatsache, das es in anderen ländern noch profitabler ist, macht die sache hierzulande nicht unwirtschaftlich.

kleines rechenbeispiel:
ich zahle etwa 22cent/kWh,
die "produktion" eines bitcoins kostet mich bei momentaner difficulty etwa 47.5cent,
momentaner marktwert eines bitcoins etwa 5€uro,
bleibt unterm strich ein gewinn von 4.5€uro pro bitcoin (nachdem die hardware abbezahlt ist).

das es in anderen ländern nur 10-30cent kostet, einen bitcoin zu produzieren, stört mich dabei nicht wirklich.

let me get that straight:

first, you want a fixed BTC amount per month,
then you think about 25% of the BTC generated,
now you want to base it on difficulty. 

and although you want to commit the whole service for BTC ONLY,
you now offer to accept GOLD. 

all that doesn't really make much sense to me.