I cannot start cgminer with more than 1 antminer U1 connected. anyone else have this issue or a solution? it seems like the golden nonce process overrides the cgminer process of connecting to pools, and it freezes up before the top section of info (hashrates, pool, etc) can appear.

makes restarting a stopped miner a PITA because i need to unplug all my usb cables first

+1     I am planning in USB risers because
a) they will last longer because there is no flimsy ribbon cable for it.
b) they look better - The rig wont be a centerpeice, but it will hopefully be visually appealing.

saw your PM - i actually ordered some ebay risers last week but at this point might still buy locally for $10 more just to get things going sooner than later.
on review of some other builds - it looks like going with a 4-slot mobo would be almost $100 less than a 6-slot variant, and that BAMT can run on only 1-2gb of ram (another $20 saved)

after some price checks, it looks like the local Tigerdirect actually has very good deals and is competitively priced against NCIX.ca and newegg.ca - They had about 12 of the Sapphire r9 270x in stock today (only 2-3 of the MSI 280x) at a recent price drop from 270->240. a few different guys in the store knew i was looking for mining gear before i even told them, and pointed out a few good mobo brands (in 6-slot flavors).

RONA has some amazing storage crates that are about 20% bigger than milk crates and I currently use some for holding 2 antminers + psu each. using one for a GPU rig would likely be pretty simple and extremely easy to stack.

few remaining questions:

1) AM3 vs 1150 vs 1155? It looks like these all offer similar benefits, but AM3 seems to be about 10-20% cheaper for both the mobo and the CPUs
2) any issues i might run into using zipties to support the cards and mobo? obviously i dont plan to let them be loose and swinging around, but without a GPU in fornt of me its difficult to visualize the tie-points i could/would use.
3) if using USB risers, should the mobo be vertical? most builds have the mobo flat but this seems like an invitation for dust buildup or for foreign object to land on the board and short something. with a crate, vertical orientation seems simple and better
4) anything else i should consider? Is it as simple as assembling the rig then booting it with a BAMT-loaded usb drive and then tweaking settings from there? do i need to run a monitor from the mobo or one of the GPUs and do i need dummy plugs?

looking for a bit of a confirmation on a build before I go out and throw down $2000+ on it:

MSI Z87-G45 GAMING  ($160)
2*600W power supplies (full 600w on 12V) ($40 each BEFORE a $15 MIR)
cheap celeron processor (about $50-70)
2x2gb ram ($40)
6x Sapphire R9 270X dual-x  ($240 each)
6x usb risers ($25 each)

USB w/ BAMT
keyboard
mouse
monitor

Does this look like a good build? Ive read the sapphire cards can be pushed into the 450-480 khash range, so 2.7Mhash/s for about $2250. ($0.80/khash) I plan to use either a milkcrate or a shoerack and a few zipties to hold everything in place.

My biggest concern is of being late to the game. scrypt ASICs are close, and will offer about 1/10th the power draw. I expect these to roll-out on a large scale in the next 2-3 months. The GPU rig would require about 6-9 months to break even - maybe 3-4 months if mining doge, having BTC value rebound, and considering a 50% resale value on the components to gamers.

I am about to get a 6-card (sapphire R9 280x) rig put together this week, and right now am looking at about $3900 for all the parts (cards, risers, frame, corsair 1200i +850w PSUs, etc). Is this a good price, or should I be using a few lower-budget items?

Trying to figure out what the $/kh ratio is that people are looking for when they build a GPU farm.

also: is GPU mining going to be dead in 3 months when scrypt asics become the next big thing (gridseed is close, they just need to make a 40-chip board rather than the hokey 5-chip cylinders that cost more per khash)? or will there still be good profits in mining?  I am just worried that I will put $400 into it, make $1000 [profit] in 2 months, ASICS will come out, and I will make another $1000 in the following 3 months, then by the end of 6 months GPU mining is obsolete and I am left with a rig that has little if any resale worth.

are server supplies good for GPU use? I want to make sure its safe to do before i go wiring a hokey DPS-800GB into a valuable GPU rig

I don't understand that much polish - you gotta post english on an english forum

20AWG cables are unsafe - you should not attempt to run more than 200W through a single 20AWG PCI-e lead, even then they will get warm.
18AWG will be safe for closer to 250-300W
16AWG is what you should use for high-end GPUs, can safely run 300W through a 6/8-pin PCI-e

no way - look back through this thread and it is clear - while these can draw as little as 360W, most power supplies with under 400W for stock speeds or 450W for overclocking will simply cause errors such as reboots, chips marked with 'x', or inconsistent hashspeeds.

I don't know of anyone at the moment - local production costs can be pretty high compared with overseas options.. However, if someone does setup in Ontario they should let me know

+1 

all you need is a paperclip or other 0.5" wire to short the PS-ON function to have the powersupply operate without a mobo

Im definitely keeping an eye on the WPC. Ive got a fat mining wallet right now and am waiting for someone to bring a product at a leading price point (Bitmain at 1.45BTC is no longer relevant - should be 1.2BTC). 

this. Have 2  hot-swap bays for common 600-800W server power supplies.

^what? Your logic is not very solid.

He was stating that the average hashrates (3 and 7 day periods) are both trailing under 500GH, closer to 430-450GH.

According to YOUR math, Its actually >2.568 blocks/day that should be found, especially if the mine actually hit the 1GH/share mentioned in a recent update (in which case, closer to 2.59 blocks/day - but lets use your numbers....

ACTUAL/EXPECTED = 2.25/2.568 = 87.62%       

over the past 18 days, the 500TH mine has been operating at 13% less than the expectations - this is pretty massive seperation

I think we are still 6-12 months away from any reliable immersion/2-phase solutions for bitcoin that do not cost an arm and a leg to cool technology with only a short useful lifespan.

Its funny then that your hosted groupbuys are so expensive - I guess you must be making a lot of profit on that.

This is a step up from mining at home. commercial power costs and availability, 600V A/C system, and the benefits of getting equipment out of your house where it is going to get VERY hot and noisy in the next 4 months are all motivators for me.

I looked at co-location. What I found was that I could (if lucky) fit about 10kW of equipment into a rack based on the antminer power use and size, and at a cost higher then the rent for this small farm. I will have lots of space - equal to 3-5 racks - plus lots of power. I also have people on-site who can perform basic upkeep and the location is pretty accessible for me to do larger adjustments.

This location may just be the first step. If 20kW of power capacity is reached - either a new transformer will go in for pretty small cost, or I will start looking at getting a private building with >80kW capacity - possibly even in another province where power costs are 30-60% less than Ontario.

Not sure why your very negative outlook on this - at 20kW it is a short-term solution (4-9 months before power capacity is reached and a fund is started towards another location and more equipment) and will act as a test-bed for a lot of things that could not be done in a residential location where <5kW can be reliably accessed without major work.   If you have been following some of bobsag3's work with an american industrial building converted to run a few dozen TH along one wall you might better understand my thoughts.

go to network adapters -> ethernet -> ipv4 properties -> set the laptop ip as 192.168.2.201 and gateway as 192.168.2.1   connect the laptop and miner directly with a single ethernet cord. go to 192.168.2.99 in browser and then change the antminer settings

Its an easy fix at any electronics place. going somewhere that does cellphone repairs of PS3/xbox modding will help you find someone with the precision soldering skills to fix it up fast, as long as there are still contacts on the capacitor.

Unless you are VERY good with a soldering gun, take it to someone who is. Its not worth botching a $10 job and wrecking your antminer totally

You did a good job of that      

Got a good quote finally for electrical work, should be just under $1000 all said-and-done to install 100A of 120V power and 60A of 208V. Its expected that 18-22kW of this capacity will be available from the main transformer without interfering with the host business.

The outlets will be put in place Tuesday, and at the same time I will get some of my own initial hashrate in place and make sure the network is configured correctly. I promise to bring back some photos of the available area, the new power connections, and some of the initial hashrate going live. I plan to move in my full 1.67 TH by the end of the week.