Topic: [ANN] Spondoolies-Tech - carrier grade, data center ready mining rigs - page 454. (Read 1260350 times)

Generate a tonne of negative pressure at the hot side of the unit and forget about your little puny fans.

If an SP30, using 4 of the most powerful 80mm fans, can cool 3kw with a dT of 38C, how do you propose you can cool 10kw in the same container?

How can your DC bring the dT down to 12C if the machines are limited to ~400cfm?

I disagree.


Aren't you German? You have no excuse for using CFM. Use some reasonable units, like m^3/s (which would be 4.25) or even m^3/hr (which would be 15300).

Anyway, I find it funny that you use that airflow rate, since that's almost exactly what my DC is specced for.

Let's say you've got 40U of SP30s in a rack. That's 60 kW. 60 kW is 60 kJ/s.

The volumetric heat capacity of air is about 1.21 kJ/m^3/°C. If you have 4.25 m^3/s of air, that's 4.25 * 1.21 = 5.14 kJ/s/°C.

If you divide your power by your airflow, you get a ΔT of 60 (kJ/s) / 5.14 (kJ/s/°C) = 11.7 °C. This means you have enough airflow so that the exhaust air is only 11.7°C above the temperature of the intake air.

Right now, my SP30 is running with a ΔT of about 38°C when running in an air-conditioned room all by itself. If your DC's fans are pumping enough air for a ΔT of 11.7°C, you are supplying 3.26 times as much air as your SP30s need or are designed to use. You could either use 1/3.26 as much airflow for that much power, or you could cool 3.26 times as much power with that airflow. If Spondoolies or someone else made a miner with 10 kW per 2U that could tolerate a ΔT of 38°C, then 4.25 m^/s or 9000 cfm would be just about right.

You could also just use that much airflow without increasing your loads, and then the ASICs in the back of your miner would end up being (38°C - 12°C) = 26°C cooler. This is what my DC design does.

You will see a performance penalty for running an SP30 on 110V or 120V. That performance penalty will likely be about 7% to 13%. I strongly recommend you either wire up a few 230V or 208V outlets for your miners, or use a hosting service that provides 200+V. If your electricity is above $0.10/kWh where you are, you may even find that using a proper hosting service saves you money on power, in addition to giving you extra GH/s. But maybe I'm biased, because I'm a hosting provider myself. Anyway, the directory of hosts is here: https://bitcointalk.org/index.php?topic=622998.220

If you insist on running your SP30 on 110V, you will find that each SP30 requires its own 20 amp circuit. I've been able to run mine on 15 amp circuits as long as those circuits didn't have anything else on them, but the margin before circuit breakers tripping was small, and that was at 122V not 110V. You will not be able to run more than two SP30s on four 20A circuits, although you might also be able to stick an Antminer on each circuit if you're lucky.

My SP30 gets about 4.1 TH/s when running on 122V, and about 4.5 TH/s on 230V.

I moved my SP30 around within one room the evening of the day before yesterday (about 36 hours ago), and the result was instability at the 1190W/1170W I had it at. I had to drop the limits on each PSU by about 70 W in order to regain stability. The issue appeared to be that both power supplies had become more susceptible to overheating. I don't know why performance decreased so much with such a small move (about 6 feet). My rough visual evaluation is that the new location should have slightly better airflow than the old. Intake temperatures are measured as being about the same, too. One of the PSUs is on a different electrical circuit (fed by a different breaker), but it's the same voltage as before, and it's fed by the same transformer (although possibly a different winding or a different part of the same winding).

Anyway, I currently have my PSUs limited at 1125 W (top) and 1105 W (bottom). Hashrate is about 4046 GH/s. I might be able to squeeze a few more watts out of each, but I don't have time to play that game right now. Maybe later. I'm curious to find out why the available performance dropped. Maybe it was airflow, or maybe it was a change in the thermal conductivity of the case to the steel stuff I had it sitting on before.


This means that if you set the limit on the PSUs too high on 120V, you just get rapid PSU overloads, and your hashrate suffers horribly. Careful, all you other 120Volters.

Where I'm sitting, the guys get at least $100/hr to write some code, and I'm sure that cgminer took a little longer to make and maintain. Especially with new technologies. But most of our code is unique and built on order. Looking at the quantity of SP10 and SP30 manuafctured (and some delivered) already, it makes sense to donate something for a good piece of open source software used in the setup.

In the end, donations are tax extempt and help both sides of the equation.

Oh nm just saw your reponse its a L6 vs an L5 30R got it

thanks!

That won't work.  If you buy all that stuff you'll quickly find that the L5-30R receptacles on item #2 don't match/fit the L6-30P plug on the PDU (#3).

Edit:  Instead of the #2 you linked to, check this one out:  http://www.amazon.com/L14-30P-2x-L6-30R-Splitter-Cord/dp/B00CP7PIRG/ref=sr_1_1?s=electronics&ie=UTF8&qid=1407524517&sr=1-1&keywords=L14-30P+to+2x+L6-30R

I know, but there is only one reason and that's not enough money for a SP30. Lack of 1k$.

The sp30 is cheaper per GH for both you and spondoolies.

It is also more power-efficient an more quiet, so why would you prefer a sp10?

Since June!

No more SP10?

Yup, plug each PSU into it's own circuit and you'll be good.

I'm ready to order two SP30's however am somewhat confused on the power requirments for the units.. When I look at the pic and try to understand the tech docs these look like two standard server Power Supplies with a 110 plug.. At my rack I have 4 20 amp circuits with the standard american wall outlet .. So, if I understand this right I can plug each PSU into its own 110 circuit and I should be OK >? Does this sound correct ? I have to wait 4 business days for my ACH transfer to complete so I have time to work this out.. Also I will be using Bitcoin to buy, so once I make the purchase will the first block confirmation put me on the list for the September delivery batch ? I'm really excited about getting these two units and look forward to testing them out for the users who frequent my site and IRC chat.. I have a lot of people asking about the units, so I'm trying to learn as much as possible .

so to make a long story short i could start with this  :

1)

http://www.amazon.com/Conntek-14330-1-5-Foot-Adapter-Connector/dp/B001TO7130/ref=sr_1_7?ie=UTF8&qid=1407514332


to link from the dryers receptacle

then pair that with this :

2)
http://www.amazon.com/L14-30P-2x-L5-30R-Splitter-Cord/dp/B00CP7QBRW/ref=sr_1_cc_3?s=aps&ie=UTF8&qid=1407518580&sr=1-3-catcorr&keywords=125%2F250+splitter

that's 10 feet long so good enough length for me.

Finally attach two PDUs  (one to each of the female splits)

3)
http://www.ebay.com/itm/APC-AP9571-Basic-Rack-Mount-Power-Strip-Distribution-Unit-PDU-12-Slot-1U-/111430262755?pt=US_Power_Distribution_Units&hash=item19f1c2dfe3

so one PDU can be used for each SP30

Tell me I won't burn down my house with this setup lol ?

It is a bit high, the actual intake temperature might be around 3°C lower than what the sensor says.

26°C is an acceptable temperature for a standard density datacenter though.



You can always share your experience with a certain datacenter in the hardware hosting thread (service discussions threads).

I have a couple SP10's hosted. Are these temps within normal operating? If they aren't I'll need to contact the host.


Temp Front / Back T,B  29 °C / 65,78 °C

lol that's what I'm saying

That's not a bad deal at all. That's like $4000 + whatever the mining rig makes. So basically soon as that thing started to run it was making %100 profit. I'd say that is a great exchange for writing some code.

240V is ok as input on AP9571, however it is rated for 24A and each Sp-30 is at least 12.5A at 240V, more current if lower voltage.