Topic: FPGA Inflection Point - page 2. (Read 7996 times)

56k modem !

what decade are you in ?

Anyway, you don't need any of the items you listed, once you have your first machine, that is.

I have 1 monitor, 1 keyboard, 1 mouse, KVM, and 4 machines

3 are dedicated miners with bootable usb with Linuxcoin

Okay, okay, fans might be a good idea

CoinSpeculator, Bravo!!!

Damn close to calcs I've made privately half a year ago.

While the price figure for a mining rig is debatable, the point about government involvement is interesting. Anyone with more technical knowledge want to tackle that one?

$50 for a quality PSU that can support 600w+...? who's being ridiculous here...? I have two really good 630w/650w PSUs and would definitely be nervous putting three 5830s on them, hell, even three 5850s (which use less power) would make me nervous...

LOL, u would have been better off piggybacking onto fpgaminers thread!
i went thru that whole thread yesterday and not yet having gotten into mining but planning to do so i have a sincere interest in trying to figure out what to buy for the longterm.  i appreciate u trying to get this thread going and i hope it matures to some more helpful information for us all.

by undervolting from 1.088 to 0.95V I think I could get my 5850s to about a 30% higher hashing efficiency (hashes/W)

if you could undervolt further it might get even better

Don't forget the DESK CHAIR!

case? operating system? fans? keyboard? mouse? printer? scanner?  fax machine?  56k modem?!?

Ya.... what's the harddrive for?

I use a revisor image on a thumb drive for 20+ PCs.....

I'm pretty sure I can boot it in < 256M of RAM.

In my opinion, $500 is a bit optimistic.  I would say $650 just based on the cost of the mainboard with legitimate (not hacked, not cabled) PCIe slots, PSU and whatever crappy case you can find.  A DVD-ROM or permanent storage would be nice..... it sucks booting 20+ machines at a time with a thumbie.

Has anyone tried to build arrays of ITX boards?  Some of the newer ones have at least one PCIe slot and don't cost more than $100.  No idea what hell you would have to play powering the video card.....

USB = $1

Cheap Memory = $10.

You people are ridiculous.

hard drive? memory?

The GPU's come with sata to 6-pin connectors.

Power Supply Unit.

power support unit?

what is a PSU?

Sorry for derailing your thread, but the Sapphire 5830's I've been looking at needs two 6-pin PCIE power connectors each and from what I've read need ~200W each. Can't find a PSU on Newegg that has enough connectors and is 700W+ for under $100.

Newegg?  Only need 2X350.  Maybe even a 650 would do it.

I'd like to know where I can get a PSU that supports 3x5830 for $50.

So everyone is well aware that GPU mining is the dominant way to make bitcoins right now.  There is quite a bit of talk about the CIA or google setting up a FPGA or ASIC farms and owning the network.  What I would like to do is examine some of these events:

A) The point where GPU mining is worthless.
B) The point where FPGA mining is more profitable.
C) The raw capital cost of instantly putting the network into these conditions.

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First let's start with what appears to be the cheapest setup right now.

3 x 5830 = $320
Motherboard = $100
Power Supply = $50
Processor = $30

Total = $500

My 5830's are putting out around 270Mhash/s, but I've seen 300 possible.  Approximate power use is 200W each.

900 Mhash for $500 and 630W.  1.8 Mhash/$, 1.5 Mhash/W

This machine would produce around 2 coins a day and use 15 kwH of electricity.

Assuming electricity is about 13 cents, this means we currently make ~$20 at a cost of ~$2.

Which leads to point A:

Difficulty has to increase approximately 10x current values at current prices to make GPU mining by existing setups unprofitable

It is clear that we will all be mining for quite a while unless prices fall drastically.  Investments in rigs are still profitable at this point, paying themselves off in about a month.  Considering another difficulty increase coming up, maybe 2 months.  Network size should continue to grow.

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From what I have cobbled together in the various FPGA threads, FPGA's have essentially the inverse cost of GPU's.  Rather than being about 2 Mhash/$, FPGA's are 2 $/Mhash.  In exchange for this you have virtually 0 power cost (for the sake of these 10,000 foot projections).  Allocating our identical $500 gives us a rig that might do 250 Mhash/s.

So we've invested $500 for a rig that makes ฿.5 or $5 a day.  We are tasked with finding the point where GPU mining only yields the same amount as FPGA's.

20$ * 1/x - 2 = 5$ * 1/x

x = 7.5

Difficulty has to increase 7.5x current values to make FPGA's more profitable at current prices.

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To push difficulty to the level of 0 profitability for GPU's, hashing power must go from 4 thash/s to 32 thash/s at current exchange rates.

To push difficulty to the level of FPGA>GPU profitibility hashing power must go from 4 thash/s to 25 thash/s at current exchange rates.

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At $500 per Ghash the US government would only need 16 million dollars in GPU miners with a power cost of $72,000 a day before everyone else on the network would give up mining.  Pittance to prevent an upstart currency from toppling the dollar.

An organization looking to make a long term profit could invest around 50 million in FPGA's, and while not completely controlling the market, eventually incentivize all comers into buying whatever system they developed.

Another point to make is that the difficulty will automatically double in 2013.  We will see if GPU power per price increases, but I doubt it.  Bitcoins are trivial in comparison to the video gaming markets as a whole.  My guess is that this will be the tipping point for GPU's assuming prices don't change drastically.  FPGA's can almost always be justified as a positive longterm investment, while GPU's will likely lose their value in a year or so.