Topic: GROUP BUY - AVALON6 - $1100 - Closing Jan 12 at 6:00 PM EST - page 10. (Read 11510 times)

Wow, I never thought a Kill-A-Watt could read a PF that high except on an incandescent light bulb!  Is .97 PF an actual Kill-A-Watt reading on a bitcoin miner?

Yes I know.  I owned a KNC Mercury back in the day and they were having Jupiter users with burned up supplies.  They were jumping the connector.  Those supplies were designed for motherboards not miners.  The respective voltage loads are way different.  I suspect some supply manufacturers were using a low voltage rail for the maximum current ramp circuit as the low voltage would reach its limit quickest but jumping the connector and never putting a load on the low voltage rail, when a user would turn off the miner, the supply's low voltage rail wasn't brought to ground quickly enough then the user turned the Jupiter back on while the maximum current ramp was still high and bam the voltage spiked blowing the capacitors on the miner board sometimes causing the board to burn.  

By the way the solution there I think was the pre-fab jumpers with a resistor to the low voltage rail allowing it to be drawn down to ground when the miner was shut down.  They sell those on Ebay.

Power factor should be as close to 1 as possible. A good server PSU will have active PFC on the input, which typically yields a PF of 0.97 or better. 0.7 is pretty bad and if you run too much power at that level your utility provider will hate you. My bill goes up 1% for every 1% my PF is below 90% (averaged for the whole shop).

I have some Avalon6 already in hosting; the most recent ones were put with a Dell 750W server PSU per blade. They're running just fine far as I can tell.

I wish I had stock right now, but we won't for another month or I'd probably offer a discount deal for participation within this group buy. We're working on an interface board that's compatible with DPS800 and DPS1200 edge-connector server PSUs, probably the ones kilo just talked about. Maybe next month.

That is a ton of work for little savings, the server PSU's like the 1000w and 1200w can be had for $40 or less.  Simply jump the "on" with a resistor and solder on some wires and done.  I have a few I did recently and can post it on the PSU thread here if you want.  Also the 1200w has a Pot to adjust voltage and amperage (I have a thread on that as well). Here are the links to the 2 threads:
PSU discussion:
https://bitcointalksearch.org/topic/update-large-review-of-finksyj4bbrwock-server-psus-compared-to-atxpsu-photos-up-1284563
PSU Voltage adjustment (by yours truly  )
https://bitcointalksearch.org/topic/overclockovervolt-the-avalon6-with-a-dps-1200fb-made-simple-1294058

It can be shipped direct but I will have the details of how that will work tonight.  Phil is getting several of the units for to ship out to people as well

You guys with good power supplies would know.  What power factor does a Kill-A-Watt give for a good supply?  Personally I've always gone with cheap LED supplies then added a heat sink to the bridge rectifier, changed out the single turn trim pot for a 20 turn, improved the thermal paste on the power transistors then replacing the fans when they get noisy.  Also I add 3½ LEDs measuring the voltage at the PCIE connector.  With a C1 I use four 360 watt 12v LED supplies, one on each blade and a fifth to power the radiator fans and pump.  While I was considering the buy of an Avalon6 I was considering buying four new 5v or 6v 360 watt power supplies for under $30 each, putting a digital readout on each and again at one of the two PCIE connectors on each blade, putting two in series for each blade.  Putting 12v supplies in parallel burns them up.  So, with two of these improved cheap LED 12v supplies on an S3+ right here that I have a Kill-A-Watt monitoring, I get 120.2VAC, 0.70 power factor, 59.9~/s, 554VA, 388 watts, 4.62 amps.  So, I figure the losses using cheap supplies would show up in the power factor figure and wattage.  Can someone tell me how this compares with quality supplies?  Thanks.

What I'm powering with these really doesn't matter.  The 12vdc would appear as a resistive load so power factor doesn't apply.  I really can't get a good reading on the DC current.  I considered buying shunts but then the cost...

Excellent, I will wait for Philip's PM with total and already saw he created a payment address. Will they ship direct to everyone or someone receiving them all and re-shipping? I saw NJ somewhere, I am in NY so just curious.

Thanks Again,

PPOC - 2 units
Kipper01 - 1 unit

You have been added 

I will do one avalon 6 at 2.5 BTC

Just found this link, good thing as I was considering buying 2 units direct.  Please put me down for 2 units and I also need a PI controller. Will be shipping to zip 12110. Philip, I sent you a PM asking about the Avalon before I found this group and saw you are doing the escrow for the buy.

Anyway, have not done a group buy before so just let me know what I need to do and when and where to send the funds, I have the BTC already allocated for this.

Thanks,

Yes efficiency would be better off two different PSUs. If you can get your load on each PSU to around 50% that would be most efficient (maybe not on your wallet).
Graph below is for the PSU I plan on using:

If I want to get more efficiency I could add another PSU and hit right at the 50% mark or just run on 1 and still be fine. Thats why I chose the PSU i mentioned earlier. Of course you guys with 240V can just laugh and enjoy you're superior server PSU efficiency.

Yes that would be good.

If I'm thinking right, these Avalons have separate 12V rails per board so if necessary you can run them off two PSUs, probably want at least 600-650W rated each. But a decent 650W PSU to run on 120V shouldn't be hard to find.

Usually it takes about 6 months for me to cover the cost of my miners

Honestly this year with the halving if the price doesn't increase I dont care how much you pay in power. It'll be hard even for the .03pkwh to return any money off of a new investment and with these 10% increases every time!!!

Okay sounds o
Good to me.

I will get everything finalized tonight with Yan, we usually speak in the evening. 

Unfortunately I dont have access to a 240V supply at this tie so i'm stuck at 120V 

Honestly I'm expecting to lose around $450-$600 this year per unit with mining difficulty increase and the speculation that BTC price will increase at around 1.1% per month. If it grows more than that I'll be happy, but not holding my breath. If I can mine with a unit for a year and just cover costs I will be happy. You guys with power under $0.07 or being hosted should do ok though. Any one else do some cost/profit estimation for the next year?

I'm going to running mine on the same psu.
If the deal goes thru I'll order one

I will use 240 volt server psus

Your psu choice is borderline if you go full speed.

What PSU are you guys planning on running your A6's on? I'm going to use the Corsair RM1000 - Gold http://www.nextwarehouse.com/item/?1473361 since i've seen it works fine on some other members rigs, but just curious what you guys will run.