Can OP or anyone else who has a 7970 benchmark vanitygen?

https://bitcointalk.org/index.php?topic=25804.0

You want to use oclvanitygen.exe

It should only take a minute or two.  Make sure the device you are going to  use is not in use (if you are using cgminer you don't need to stop just (G)pu menu (D)isable, then GPU #)

oclvanitygen -d 0 1Bitcoinz    (0 = device # and the string is the address searching for 1Bitcoinz is impossibly long which prevent the generator from getting lucky too soon)

Then just let it run for 30 seconds or so to normalize any variance.  You should see a line like


PRovide the MKey's and the core/mem clocks. 

Thanks

Even compared to FPGA which do exist the return isn't worth the risk. 

As a tech lover it sucks that cheapo CPU, cheapo RAM, usb stick, decent MB + lots of GPU = winz.

As a capitalist I own 5 such rigs. 

I also am not just thinking of CURRENT FPGA but a year is a long time in silicon world.  FPGA designs will only get more cost effective.  28nm chips likely will be reasonably available this year.  Who knows what the pricing is but FPGA getting 25% or 50% higher efficiency (MH/$ and MH/W) is certainly a possibility. 

All that puts a damper on long payback periods on GPU tech.

I dont think its possible on radeon 6 cards. You can underclock the ram only a few 100 MHz, as far as I know.

So I decided to run some more numbers, and found out just exactly how bad of an investment this could potentially be.
So lets assume that IF a 7990 had 2 cores capable of 600 Mhash/s each at stock clocks, and IF they pulled the full maximum of 375 watts for a PCI Express card (2x 8pin @ 150watts each = 300 watts, plus 75 watts from the slot), and IF I could get all 18 slots populated and working with virtual machines or whatever technology, and IF it cost me a conservative estimate of $25,000........

.......that would mean numbers such as the following:
21.6Ghash/s per rig
~7500 watts power draw at the plug(s) (assuming 95% efficiency, which is more common in server-grade power supplies)
6-8 U rack spaces, depending on how it was architected.

Now, if we assume for a moment that the BFL Rig Box exists and works at the numbers stated, that is as follows:
~$25,000
50 Ghash/s
2500 watts
unknown rack spaces

I suppose this serves to illustrate how badly FPGAs have the potential to kick  whomp  BLAST the ass of video cards into next week.

Since my power is 9 cents kw/h, I decided to do an ROI calculation. For the custom monster machine with 18 video cards, ROI is slated to be ~250 days, assuming the difficulty and price remain the same (yeah right ). For the Rig box, it is 95 days. Of course, the video cards and waterblocks have known resale value, but damn.... less than 100 days. I STILL am not sure whether I want it to be true or not.

EDIT: minor spelling corrections.

MagicalTux is Satoshi Nakamoto, of course. English speaker in Japan, who else would choose a Japanese name for a Pseudonym? Runs the big exchange and has extracted the forum from his former alias by "acquiring" it with MtGox...

"© 2013/2013 bitscalper.com"

Must be easy to auto trade when you're from the future.

gotta risk it to get the biscuit
the real challenge will be seeing if I can get my money out of there

Well my estimates were based on $650 6990s, $110 waterblocks, a $2000 host computing board, a $650 backplane, and six PSUs hopefully being less than $500 each. The unfortunate issue is that the manufacturers of the waterblocks don't publish technical specs such as flow rate at a certain pressure, recommended pressures, etc. so my numbers might be bad estimates.

However, from my calulations, this radiator should be able to dissipate all the heat from 18x 6990s when used between 0 and 1 Bar of pressure, because it is rated at 10 horsepower heat dissipation at that pressure. Yeah I know it is an oil cooler, but there shouldn't be any reason for it not to work with glycol or similar. The heat dissipation table is on the catalog page at this link.

got all 4 2 days ago, will replace a few tonight.

Wow, such PSUs might be perfect for my 18x 7990 rig, if anyone decides to make them. 18x? Yep - with watercooling, VT-d, and a few virtual machines, it *should* be possible. Take a look at this: http://www.chassis-plans.com/single-board-computer/S6806-backplane.htm

240V is easier to make an efficient PSU out of, but 96% is totally awesome.

Anyone wanna invest?