I couldn't get mine to do more than 650KH/s so I put away for a while. Last night I tried again and with any TC over 10240 cgminer starts with error -4 saying it couldn't load the kernel so I was going to flash the BIOS but decided to try different configs first. Now "--thread-concurrency 10240 -g2 --gpu-engine 1050 --gpu-memclock 1650 -I 13" is doing 720KH/s and I think there's room for more tweaking. That's with stock cgminer-3.7.2 so I want to try one of the updates.  Suggestions for which one and any adjustments to config?

Very cool. Will we be able to schedule a time-based auto-payout?

And there was much rejoicing.

-2j

PS: What would you consider a tiny threshold?  (I hope I wasn't adding to the problem.)

Seconded, or maybe just a distributor: ship a selection of units as slowly/cheaply as possible and when someone in the US buys a unit the distributor ships it.  If there's enough business the distributor may decide to buy a bunch and resell.

I think I know someone who would be willing to do this so PM me if you're interested.

I'd love one of your racks but I missed your black friday sale so between that and shipping the US it's just outside my price range. Any chance you could extend the coupon code?  I'd really appreciate it.  From the pictures the racks look gorgeous.

Thanks.

-2jase

Nope.  Well, you can get them to be relatively quiet but only if you run them at lousy hash rates .  I've tried a bunch of different brands and none are actually quiet.  Remember that you're turning ~200W of power into heat on a tiny piece of silicon so it's going to get very hot and you're going to need a lot of airflow to cool it.  Airflow ~= noise.

My experience:
- XFX single fan 7950 sounds like a jet engine even at 50% fan. It's picky about overclocking and struggles to do 600KHs but needs tons of case cooling and it's still LOUD.
- Sapphire Vapor-X 7950 cools well, runs pretty fast, but doesn't handle undervolting well. Does about 630KH/s.
- Sapphire Dual-X 7950 cools pretty well, a bit louder than vapor-X and will do 670KH/s.
- MSI Dual Frozr 7950 is my favorite. Fans cool really well and it'll sustain 690KH/s. Still loud at that level but also stable.

I also have a Dual-X 7970 that'll do 730KH/s (it'll run 750KH for a day or so but crashes miserably, needing a hard reboot) but I'd stick with the MSI 7950s.  Also, I can't get my Sapphires to down-volt though I haven't tried loading new BIOS either.

Last comment: My 2-month old Vapor-X had a fan bearing fail the other day so it barely spins.  Amazon is sending me a replacement but this is the first GPU I've seen go bad so keep an eye on them.

To quote the great philosophizer Butthead "If everything were cool, uh, how would you know?"

-2j (surprised and saddened that spellcheck doesn't flag "philosophizer".)

Dude, you're amazing.  Thanks!

2jase; 16; 7.68; 18iZzwsA1AUEFfkPaoREcNU9eDFQ9pusuo

Do you have TV coax running into the basement?  If so I'd suggest a pair of MoCa bridges at around $50ea.  I'm using MoCa to to bring IP into my bedroom because wifi has a hard time going through 3 50-year old walls with thick metal lath backing the plaster.  It's fast and solid.  If you have a TiVo Premiere you only need one external bridge since it has one built in.

I got the d-link 7-port hub tonight and it'll handle 6 BEs without a problem, though with 7 plugged in cgminer ends up idling one of them at a time.  Between that and a small 4-port I had lying around (with a 2.5A PS) I'm running 10 BEs off of my Raspi for a total draw of 35W measured at the wall by a kill-a-watt.  Time to return the Juiced hub.

@klondie_bar: good point - I should've mentioned that. DX delivery took about 5 weeks for my last order.  By the time it arrived I'd forgotten that I'd ordered a 5mw green laser pointer for $7 and man was I surprised at how well it works and how far away you can see the beam.  No, I'm not shining it any any airplanes (I like not being in jail.)

@pidge: nice setup and extra points for the custom duct work.  ;-)  I wonder if you could use a 5-10A wall wart to replace the underpowered ones that come with most of these hubs.  Sure, yours is much cleaner, but with kids, pets and a clueless in-laws around it would be safer (for them and the equipment) to go with something a bit more boring-looking and less exposed.  What do you think?

$4 is a decent price for short USB extenders but dx.com has 'em for $1.50:  http://dx.com/p/usb-2-0-extension-cable-20cm-28982

@dwdoc: All of the Amazon feedback on that hub is bad - have you noticed any high-pitched whine? And is it still behaving well?  The clearly confused product description (I'm guessing "2.5V AC adapter" means "2.5A AC adapter") doesn't inspire confidence either but if you still like yours I'll probably order one too.

@Nemo1024: Thanks!

@lano1106: I'm running Ubuntu on the PCs and I installed minepeon on the Pi last night since I have a 7-port D-Link powered hub coming today. 

@myter_miles: I'm sure a PCI card would work but I'd prefer the flexibility of a hub, plus you aren't taking up a PCI slot.  I wouldn't bet on an internal bay since they're usually powered by a single cable off the mobo.

I installed Minepeon on my PI last night and confirmed that my small powered hub will run more than 1 Erupter so when the D-Link shows up tonight I'll post if I have anything new to add.  If you haven't seen MinePeon I highly recommend it.  The devs did a really nice job in automating everything I've been doing by hand for a while.  And yes, I'm donating some of my mining to them - they've more than earned it.

As much as I hate to repeat myself I posted a review of the Juiced 10-port hub in another thread( https://bitcointalk.org/index.php?topic=263577.msg2824064#msg2824064) so I'll paste it here:
-------
I bought the Juiced 10-port from Amazon and suggest getting something else.  It'll run 8 erupters but when you plug in a 9th it starts to lose contact with one, then another, then another and the only way to fix that is either restart cgminer or unplug/replug the miner.  The Anker's extra amp makes a big difference.

Adding insult to injury my Raspberry Pi can't see this hub at all, so I think I'm going to order the Anker from Amazon and return this one.

I bought the Juiced 10-port from Amazon and suggest getting something else.  It'll run 8 erupters but when you plug in a 9th it starts to lose contact with one, then another, then another and the only way to fix that is either restart cgminer or unplug/replug the miner.  The Anker's extra amp makes a big difference.

Adding insult to injury my Raspberry Pi can't see this hub at all, so I think I'm going to order the Anker from Amazon and return this one.

This isn't a show-stopper by any means but I thought I'd let you know.  The header lists "ANC/USD" and in the pool stats it says "USD/Day" but unless my math is *way* off that should be "ANC/BTC" and "BTC/Day".  Either that or it's time to go on a $1/BTC buying spree!

Great job with the pool, it's easily one of the responsive and complete I've used so I'm happy to pay the fee and to donate on top of that.

2j

2jase; 11; 10.5810588 BTC; 1L818B3kzU8cgnSN1dmb9C8Q2vuSJPfi8P; Y

PS: Really slick message-o-matic. I like it!

You forgot to include increases in difficulty. If BTC/$ increases along with diff it'll pay for itself in those 100 days. Considering what's going on with the price now, illustrating the volativity, I'd say that's unlikely. I'm confident BTC will continue to increase in value, which is why I'm still GPU mining, but you need to consider all factors and make sure you have the money and stomach for the long game.

Remember that the price of Block Erupters just dropped by 50% and once other ASICs are shipping in bulk they'll have to do that at least once more if not two or three times to stay competitive.

Don't jump in without doing your homework.

I'm 2jase and while I've been hearing about Bitcoin for well over year I didn't have the foresight to get involved when you did - nice job! I only jumped in a few months ago when it was around $100/BTC. I'd appreciate being entered into the raffle and if I win it would make a nice way to start my bitcoin portfolio.

Thanks for the fun thread and the lesson on the value of foresight. I'm hoping LTC follows in its big brother's footsteps so I may have a similar story in a year or two.

-2jase

I've been toying with FST so once I get my mining rig back up (HDD crash) I'll join you if you still need testers.

Would love to but I live in a small apartment so the box is in my living room. Tiny hands, paws, not-so-small hands, etc would find their way in. Now, if I lived in a house with a basement I'd have crate miners with a box fan and some custom cardboard ducting....

I know this is an old thread but I've managed to get my hands on 4 different models of 7950 and found that they vary widely in what settings they'll take even within the same maufacturer.  I track all settings in a spreadsheet: core, memory, intensity, MH/s (or KH/s for scrypt) and fan speed and temp.  Tune each card until you squeeze out that last bit of performance then drop each setting back a notch to keep the card from burning out.  The best results I've seen so far run from 580MH/s to 640MH/s.

Don't underestimate the importance of cooling, by the way.  In a generic case my cards ran 20C hotter than in a Coolermaster HAF with big fans. On a whim I put a small Vornado on top of a Coolermaster XB which dropped the two cards in there another 5C.

Windows and Linux seem to perform about the same with the same settings but Windows draws up to 20W more power when idle and 40 when doing housekeeping since it revs up the HDD and CPU.

If anyone's interested in my specific cards and settings let me know.  All of my benchmarking has been done by hand so far but I'm working on a script to do that for me.  PM or post if you want a copy once it's finished.   It'll be BASH so meant for Linux but it should work on cygwin and since it's using cgminer's API you could run it on Linux or Mac and point it at a Windows box.