Bitcoin Forum

Hi all,
Just wanted some feedback on running 2 900 watt HP server power supplies on an Antminer S9@110v.  I know Bitmain says it voids the warranty but in terms of safety and longevity is it safe or as safe as running the Bitmain PSU?  Your thoughts please.  

No this will not be safe.

An s9 requires at least 450w per individual hashing board. This would completely max out one of the power supplies and most likely cause it to fail or shut off repeatedly from too much power draw. Also if you try to power a single board from two separate psus to balance the load you will kill the hash board.

As has been repeated here time and again it is NEVER 'safe' to use multiple PSU's.
Can it be done? As long as you never ever try to power a single board with more than one supply ja it works but the risks of improper hookup (frying the miner or PSUs) plus the miner power now being questionable far outweigh being able to do it.

What about atx Power Supplies? 

Overall ATX supplies - even 'server' ones - are CRAP when it comes to powering miners. They were never designed to run 24x7 at or near full load nor in the fairly high temp areas that are around miners..

Why do folks insist on spending $$$ for miners and then try to go cheap on PSU's? They are critical to how a miner performs. Browse eBay, Amazon etc and you will find many folks selling decently priced miner PSU's based on real HP and IBM server supplies along with the needed breakout boards that can each easily power a miner.

Well that's what I was asking I have 2 HP DPS-1200FB 900 watt power supplies with breakout boards and I wanted to know if I can power 1 Antminer S9 on 110V.  I don't own a house and have no access to a 220v outlet. 

Yes, that is possible.

Use one HP DPS 1200 for two hash boards.

Use another HP DPS 1200 for one hash board and controller.

Turn on the power supply connected to the controller last.

Do not connect the two power supplies in to same hash board, they end up "fighting" each other.

Is there any evidence showing if these are just as safe to use as the 220V AP3++ psu from Bitmain.  See I ordered a November batch which hasn't shipped yet and I have trepidations about running the S9 on 110V with this setup.  No point in running it if in a month the machine or the hashboards go bye bye. 

The HP PSU's? Like all real server PSU's they are solid as a rock even when pushed over rated max. That is why the HP and IBM server PSU's are preferred by miners (with 220v). Running the HP 1200's at full 110v feed load (900w) yes the fans will go into hairdryer-mode and the supplies will get rather warm but the PSU's are made for it.

The AP3++ supplies are also perfect. Main advantage with them is all the power leads are already there so is plug-n-play. I have a couple dozen of the older APW3's and zero issues with them.

As a side note, you *do* know that these miners are LOUD and hot right? As in a perfect 1,400w space heater. That fact cannot be changed...

Well I'll be running it in a basement which is probably around 65C in the winter and I don't really care about the noise. 

65C in the winter?  Where do you live, Death Valley??  :D

sorry 65F.

I have a related question to this thread if anyone has any ideas.

Can i use two bitmain PSUs on a single antminer?

I am hosting my miners in a data center and they are using 30amp 208v PDUs.  Since the miners each draw about 6.5amps, i can only get 3 miners in a PDU before i exceed the 24amp (80%) limit.  Rather than buying additional 24 plug circuits for every 3 miners, I thought i could use two PSUs to power a single miner and plug each into a separate PDU that is already running 3 miners.  So bascially, running 3.5 miners per PDU. 

Not sure if anyone has tried this or if it will work.

So basically, my thought would be to have 2, 30amp PDUs for every 7 miners.  I would plug 3 miners into each PDU and then split one miner across the two PDUs using two PSUs.

Not ideal, but thought I would check to see what people thought.

If there are any other ideas on how to cost effectively increase my density in the data center, i'm all ears.  I'm finding i'm getting bottlenecked by the circuit size and the cost of larger (50amp) circuits makes it not worth it. 

Thanks!

MEK

I ran into that same problem as well...I'm all ears as I have three miners in a cabinet, would love to get another one snuck in there some how. 

Here's a little secret, Every house is wired for 240v. Then at the breaker box they split it in half giving you two runs of 120v. So they wire half the house to run off one of them and the other half of the house will run off the other. 220v appliances are run through breaker and to your appliance without modification. This only applies for a house that has its own wire running out to a a transformer.

Looks like the DPS 1200 is only specd for 75A@12V on 110-120V, ie 900W

a 14TH/s S9 takes 1400W. 

So if we're using one PSU for two hash boards isn't it running right at, or even slightly over spec? 

No because you dont want to run a PSU at 100% load all the time, that will cause an early death. Just like with breakers, I de-rate my PSUs 20%. I wouldnt push a 900w psu 24/7 over say 700-750w max.

Hi @fanatic26.

Slightly confused.  Are you saying that you /agree/ that using a DPS1200 like this is a bad idea? 

Correct, it is a bad idea. Each hashing blade pulls ~460w, which would push a 900w psu over its rated limit. While it would work for a while because server psus are pretty beefy, running hardware out of spec for that long will eventually cause a failure of some sort.

If you could find a 1200 watt version you could run 2 of the blades off of the 1200, and the third blade + controller off of the 900w psu safely.

I know a couple ways which may work for you. Some are kinda grayish so all though hounds here, please relax a minute.

A legit way to do it is to find out if the PDU is 100% rated. I often spec those and I know others do too. If that's true you can just put 4 on one PDU legally. It's best to just get the model number to look it up yourself as asking the question could raise concerns. I often use 100% circuits throughout the data center but still enforce an 80% or 90% limit to provide nuisance tripping headroom. If that's what they are doing and you ask, you could be denied. If they dind't say you can't then you can.

I'd be a little cautious as I typically see 6.5A but sometimes I measure 7.0A at 245V. If they are distributing 208V, your current could be higher. Never guess or rely on specs, always measure. Since you are likely operating in a climate controlled room, you may experience a much more consistent current draw.

Less legit is to just put the miners on it. If it runs for an hour it'll likely hold. The worst that will happen is the breaker will open. Most co-location operators are very familiar with this practice so only care if you call them to reset your breaker.

Nothing forces you to run all 3 hash boards in every miner. You can squeeze a bit more hash power per PDU by adding one hash board at a time into the 4th miner until you reach the maximum current available. Each hash board will add about 2.2A.

NFPA rules allow rounding regarding the 80% restriction. So the limit on an 80% 30A circuit is not really 24A but 24.4A.

Some co-location data centers are pretty savvy. Some measure and monitor EVERY circuit with automated systems. If you exceed the contracted load, they hit you with a charge and also a penalty. So you may want to review the agreement before slipping in more load. This is by far the exception. Most just wait for the breaker to trip then ask you if you need a 50A.

Do 1200W versions exist?

PS, I assume this recommendation from parellelminer for the x11 is also a bad idea?

http://i66.tinypic.com/2igehk7.jpg