Custom Server Power Distribution Supply

[shovenose]

So, let's say I have a lot of little computer/servers in these cases:
http://www.newegg.com/Product/Produc...82E16811321014
By default they include some generic 12V 5A brick. They have internal power boards too that take that from 12V and turn it into all the other voltages the computer needs.

Specs are going to be as follows:
-Intel J1900 Quad Core 2GHz 10W CPU
-2x4GB DDR3 SO-DIMM
-500GB or 1TB 2.5" HDD, or a 2.5" SSD

So very modest power requirements. They are fanless too which is great.
Now let's assume each server consumes on average 1.5A - that's 16W. The probably inefficient, likely low quality 12V 5A brick is pointless then.

I found this product, my only concern is, do we trust it?
http://www.ebay.com/itm/12V-20A-240W...item3cd0b1f19a

But that's 20A. I could power 13.333 servers if I assume they take 1.5A. Let's just do 12 because it's an easy number. The power supply in that link has three outputs each, meaning each V+ and V- would go to four servers. Does that make sense and would that work?

Would it be more or less efficient just to use the included power bricks or this 20A power supply? Is there any fundamental problem with my thought? Is there a cheaper more efficient design I could use?

Thanks!

[mariushm]

Re: Custom Server Power Distribution Supply

Stop trying to be cheap. Seriously man...

In the first place, if you don't have those cases already, don't buy those.

The ebay power supply will do what it says but at low efficiency and with shitty power factor correction. Maybe 80% efficiency if you're lucky.

As it's designed for leds, it may not have some protections normal power supplies have. Also, it does NOT have 3 outputs, those terminals are simply tied together, the psu has those terminals simply as a feature, as design.. there is space on the back so they put them there. There's a single 12v output of up to that many amps on it.

Buy a decent ATX power supply that uses dc-dc converters for 5v and 3.3v, such a power supply can deliver all the rated power on 12v.

A $100 Seasonic G750 can do up to 744w on 12v without breaking a sweat.

Even if the servers average at 16w, you can't just multiply. If the servers use classic hard drives, such a hard drive uses up to 2A for a couple of seconds when it starts up.

If you connect several such servers at a single power supply, you have to keep this in mind... if there's a power failure and you connect 10 such servers to your 20A ebay special, you're suddently going to have 4 amps times 10 servers or about 40A pulled from that power supply - it's either going to brown out or die. That's why you have that 5A power supply, even if the "server" averages 16w.

A very simple trick would be to simply use a microcontroller and a few 12v relays to implement a sequential boot for those servers. microcontroller starts, then every 5s or so it triggers a relay which connects a server to the power supply. This way each separate hdd has time to booth up. Problem solved.

Relays are cheap, less than $1 if you buy in quantity: http://www.digikey.com/product-detai...1012-ND/280369

Still, you're going to lose energy in the power supply in the server case also.

If you're really smart you could go with something like this:

$59 : ASRock AM1H-ITX AM1 HDMI SATA 6Gb/s USB 3.0 DC-In/ATX Power Input Mini ITX AMD Motherboard

http://www.newegg.com/Product/Produc...-491-_-Product

AM1 socket Mb, 19v +/- 10% DC in OR regular atx, you can power the hdd directly from motherboard. You won't have a DC-DC converter in the small case (as the Sentey does, and see reviews to read how well that works) to create 5v and 3.3v and waste power on that and lose watts due to efficiency, those are built into the motherboard already

DRAM HDD Estimated Adapter Power
1 1 41W
1 2 56W
2 2 60W

Standard DDR3 memory, up to 16 gb, video in cpu, gigabit lan, generally better features than intel boards.

$50 : http://www.newegg.com/Product/Produc...82E16819113365

AMD Athlon 5150 Kabini 1.6GHz Socket AM1 25W Desktop Processor AMD Radeon HD 8400 AD5150JAHMBOX

Same processing power as your Intel, maybe a percent or two faster, definitely faster if you pair it with 1600 Mhz memory instead of the 1333 Mhz or 1066 Mhz you're limited to with that so-dimm on Intel.
These Kabini are 25w rated, in reality they're going to use about 20w or less, so the whole system is going to use 30-40w instead of your 16-20w.

You can use directly 19v laptop adapters for each one, or you could buy a 18-20v power supply with lots of amps and power the systems from that single psu, without having to buy cases and so on...

Later edit: Considering it's 19v +/- 10%, that means the board should accept even 21v. It wouldn't surprise me if the board would actually run just fine off 24v, which is a standard voltage for power supplies, so you could find 24v 600w power supplies (or something like that at atx power supply prices). And even if you don't, you could also put 2 or 3 beefy (high current) in series before the dc in connector, to drop about 0.8-1v on each diode, so that the board would see 19-21v.

For example,

150$ for 600w (if you buy 10, ~ 165 for one): http://www.digikey.com/product-detai...068-ND/4386539
53$ for 300w (better value, again if you get 10.. works out at ) : http://www.digikey.com/product-detai...077-ND/4386548

Most of these 24v power supplies can even be adjusted to output between 22-24v+ (The 600w delta above at 150w can be adjusted down to 21.6v) so if you adjust it down to around 22v or less you may even be able to skip those diodes.

The jack + cable is cheap, under 3$ : http://www.digikey.com/product-detai...2186-ND/568577 ... the jack alone is under 50 cents , but then you'd have to buy cable and solder it.

[stj]

Re: Custom Server Power Distribution Supply

led power supplies are NOT fixed voltage.
they are fixed current - the voltage will rise and fall as the current use changes.

[Th3_uN1Qu3]

Re: Custom Server Power Distribution Supply

Stop trying to be cheap. Seriously man...

This.

led power supplies are NOT fixed voltage.
they are fixed current - the voltage will rise and fall as the current use changes.

And this.

I wouldn't let that kind of PSU power any computer equipment - you will be in for a VERY nasty surprise if you attempt to do that.

[mariushm]

Re: Custom Server Power Distribution Supply

Yeah, the thing is.. that eBay power supply is just a regular switching power supply.

Note that it says "for led strip light" - this refers to those strips of leds that have one current limiting resistor for every 3 leds, or something to that effect. So the strip itself does the current limiting, the strip is just a plain 12v load.

They're using the "led strip light" keywords as marketing, because people are noobs and search for led strip light power supply, they don't search for "industrial ac dc 12v power supply".

It's still a generic Meanwell (or some other chinese brand) 12v power supply, based on old half bridge or some other similar design, with poor power factor correction or poor efficiency.

You also have the idea that since the cpu is passively cooled, you don't need fans. False... the dc-dc converter inside the case and the heatsink on the cpu relies on cool air from outside the case to move through the case and cool itself. If you have a bunch of these in close proximity, there won't be any cool air outside and the systems will overheat. You'll still need some forced cooling to push cold air around those otherwise those cases will just screw with the cooling.

-

The more I think about it, the more I like that Asrock board with 19v DC input.
You could get some thicker aluminum sheets (maybe the size of mATX or ATX boards), drill some holes for some aluminum/steel spacers and screw the mb on that sheet of aluminum. Leave some space in front for 2 x 3.5" hard drives, that you can attach the same way, with some spacers. You made yourself a "blade server".

Now you can make a simple case out of some wood or other material, and simply have some channels on top and bottom spaced evenly. You can now slide the whole aluminum sheet in one of those channels.

At the end of the case, you only have the DC in jack and the network cable, and your blades will be nicely spaced so that you could screw on the end of the "case" a few 120mm fans to blow air through the blades, keeping the cpu heatsink cold and happy.

Here's something similar to what I imagine, only it's made of aluminum or steel and they 3d printed the plastic bits, you can just use some wood and drill holes into wood or aluminum : http://hackaday.com/2013/05/07/3d-pr...unting-system/

One of those 150$ Delta psus is rated for continuous 600w on 24v but it's rated for 1200w for 5s, so it will handle several blades booting up at same time.
It can be adjusted to 21.6v so 90% sure the motherboards will run straight from it.

In front of your case, you can bring a on/off switch for each blade (basically switch in series with the DC in connector). Optionally you could also put a 4-6A fuse in series with each blade (just in case a blade shorts out or dies in some way using more than 4-6 x 20v = 80-100w, you don't want it to overload the psu and take out the rest of the blades).

You could also bring in front of the 'case" the leds if you want to and a reset switch... push buttons are 10-30 cents each, leds are a few cents, ribbon cable is cheap.. it would cost you 10-20$ to make your case.

With 2 sticks of ram and one hdd, each blade would use less than 40w, because the cpu won't be at 100% load all time, but even if you budget 50w for each blade, you can safely power 10 blades from that 600w psu (it's not wise to keep it running at 600w even if rated for so much). That's $15 per blade for the power supply.
With the 53$ 300w power supplies, you'd be getting close to 10$ per blade for the power supply.

[shovenose]

Re: Custom Server Power Distribution Supply

Yeah, the thing is.. that eBay power supply is just a regular switching power supply.

Note that it says "for led strip light" - this refers to those strips of leds that have one current limiting resistor for every 3 leds, or something to that effect. So the strip itself does the current limiting, the strip is just a plain 12v load.

They're using the "led strip light" keywords as marketing, because people are noobs and search for led strip light power supply, they don't search for "industrial ac dc 12v power supply".

It's still a generic Meanwell (or some other chinese brand) 12v power supply, based on old half bridge or some other similar design, with poor power factor correction or poor efficiency.

You also have the idea that since the cpu is passively cooled, you don't need fans. False... the dc-dc converter inside the case and the heatsink on the cpu relies on cool air from outside the case to move through the case and cool itself. If you have a bunch of these in close proximity, there won't be any cool air outside and the systems will overheat. You'll still need some forced cooling to push cold air around those otherwise those cases will just screw with the cooling.

-

The more I think about it, the more I like that Asrock board with 19v DC input.
You could get some thicker aluminum sheets (maybe the size of mATX or ATX boards), drill some holes for some aluminum/steel spacers and screw the mb on that sheet of aluminum. Leave some space in front for 2 x 3.5" hard drives, that you can attach the same way, with some spacers. You made yourself a "blade server".

Now you can make a simple case out of some wood or other material, and simply have some channels on top and bottom spaced evenly. You can now slide the whole aluminum sheet in one of those channels.

At the end of the case, you only have the DC in jack and the network cable, and your blades will be nicely spaced so that you could screw on the end of the "case" a few 120mm fans to blow air through the blades, keeping the cpu heatsink cold and happy.

Here's something similar to what I imagine, only it's made of aluminum or steel and they 3d printed the plastic bits, you can just use some wood and drill holes into wood or aluminum : http://hackaday.com/2013/05/07/3d-pr...unting-system/

One of those 150$ Delta psus is rated for continuous 600w on 24v but it's rated for 1200w for 5s, so it will handle several blades booting up at same time.
It can be adjusted to 21.6v so 90% sure the motherboards will run straight from it.

In front of your case, you can bring a on/off switch for each blade (basically switch in series with the DC in connector). Optionally you could also put a 4-6A fuse in series with each blade (just in case a blade shorts out or dies in some way using more than 4-6 x 20v = 80-100w, you don't want it to overload the psu and take out the rest of the blades).

You could also bring in front of the 'case" the leds if you want to and a reset switch... push buttons are 10-30 cents each, leds are a few cents, ribbon cable is cheap.. it would cost you 10-20$ to make your case.

With 2 sticks of ram and one hdd, each blade would use less than 40w, because the cpu won't be at 100% load all time, but even if you budget 50w for each blade, you can safely power 10 blades from that 600w psu (it's not wise to keep it running at 600w even if rated for so much). That's $15 per blade for the power supply.
With the 53$ 300w power supplies, you'd be getting close to 10$ per blade for the power supply.

I assume that if the power supplies are adjusted to the absolute lowest voltage output possible, and to account for the load, it will be within tolerance of the 19V DC input. If it fries I just send it back! "Oh, it didn't work, I don't know why!..."

Reliability wise how would one of the Digikey adapters? Will it end up being more efficient long term? It says 87% which is fine. Will it last a long time? Because if I run multiple servers off one supply, if it goes out, I have a bunch of pissed off people.

I like your thinking though - I can end up spending about the same amount per server on a larger scale (more on CPU and mobo but less on case and PSU)

[stj]

Re: Custom Server Power Distribution Supply

you really need a 2 or 3 channel hotswap psu with a spare plugin.

you cant be fucking around with systems you host for other people.

[mariushm]

Re: Custom Server Power Distribution Supply

Reliability wise how would one of the Digikey adapters? Will it end up being more efficient long term? It says 87% which is fine. Will it last a long time? Because if I run multiple servers off one supply, if it goes out, I have a bunch of pissed off people.

I like your thinking though - I can end up spending about the same amount per server on a larger scale (more on CPU and mobo but less on case and PSU)

It's a Delta power supply... Delta, TDK etc do quality power supplies.
It's an industrial power supply, it's designed to be rugged and run at continuous output power for long periods of time.

The voltage on those power supplies won't go down with the load, they will be quite well regulated, within 2% of the value you set. If it says the lowest is 21.6v, then it's unlikely it will go under 21v.
Of course, if you want to you can open the power supply and make it go at lower voltage. In a lot of such power supplies, there's a resistor in series with that potentiometer, for example a 10kohm one, and the trimpot is 10-50k ... at the lowest value of the trimpot, the trimpot will be 0 ohm, so the total resistance will be that 10k that's in series with thetrimpot, so that sets the output to 21.6v or whatever's the lowest. If you desolder that and replace it with a 6.8kohm - 8.2kohm for example, you may be able to get even lower voltages.

You will have warranty on these, it fails, you return it to Digikey and in theory they give you another.

Any professional in any business like this will have hot spares, an extra power supply, extra ram, extra hard drives etc. If you don't plan to do that, you shouldn't do this in the first place.
Stuff fails, you have to be prepared for that, it's a cost of doing what you do...

[goontron]

Re: Custom Server Power Distribution Supply

you really need a 2 or 3 channel hotswap psu with a spare plugin.

you cant be fucking around with systems you host for other people.

+1

i heard a story for an engineer from comcast i know, it goes like this: one time i was told about a switch with a duel redundant powersupply and one of the powersupplys had gone out and was sending a fault code down the lines to the main building, well the supply was never fixed and a some years later the second powersupply went out and about 15 city blocks were without cable and internet for a good three days because they couldn't get to the switch. why? because the four chunks of land that this switch was between got taken over and turned into a golf course, which was gated and shutdown for the winter. but the real kicker was that the owner of the gated golf course was on the switch that died, so they couldn't get ahold of the owner to open the gates!

[Th3_uN1Qu3]

Re: Custom Server Power Distribution Supply

Any professional in any business like this will have hot spares, an extra power supply, extra ram, extra hard drives etc. If you don't plan to do that, you shouldn't do this in the first place.
Stuff fails, you have to be prepared for that, it's a cost of doing what you do...

+1000. If you decide to start offering some service, at least do it in a way which will earn you good rep from the start. If you don't give a #!*) about providing your users with quality, they won't give a @)*$ about paying for your services, either.

but the real kicker was that the owner of the gated golf course was on the switch that died, so they couldn't get ahold of the owner to open the gates!

Bahhahahahhaha.

[shovenose]

Re: Custom Server Power Distribution Supply

+1000. If you decide to start offering some service, at least do it in a way which will earn you good rep from the start. If you don't give a #!*) about providing your users with quality, they won't give a @)*$ about paying for your services, either.



Bahhahahahhaha.

Wow, way to make assumptions!
1. This is for the "budget/personal" line of servers. Cheap! There will be a more expensive "business/enterprise" series with actual server hardware or at least new, modern, i3/i5/i7 sort of stuff.
2. I do care about quality. That's why I am asking about reliability and of course I would have a spare PSU. It takes like 30-60 minutes to drive from home to office and that's an hour of downtime even if it's a two minute transfer to a new PSU.
3. How do I made it redundant? I could have an auto transfer device across two power supplies? lol.

[tom66]

Re: Custom Server Power Distribution Supply

Most industrial server power supplies use diode-ORing. That means a fair bit of power is lost in the diodes but the swap over is essentially instantaneous.

[mariushm]

Re: Custom Server Power Distribution Supply

Wow, way to make assumptions!
1. This is for the "budget/personal" line of servers. Cheap! There will be a more expensive "business/enterprise" series with actual server hardware or at least new, modern, i3/i5/i7 sort of stuff.

IT. DOES. NOT. MATTER.

If you promise something to the buyers, you have to keep your word.

You don't have to promise 10 minute replacements, for budget dedicated servers it's quite common to have 1 hour hardware replacement or even worse.

But to do that, YOU HAVE TO HAVE SPARE PARTS AVAILABLE. What are you going to do otherwise, order another psu at Digikey and wait 2-3 days and receive it?

Same with hard drives or memory - 1 out of 20-30 drives will eventually fail. Some people will probably ask you to replace hard drive just at the sign of smart errors.. you need a few hard drives and memory sticks available all the time. Can't wait to have drives shipped from newegg or whatever.

2. I do care about quality. That's why I am asking about reliability and of course I would have a spare PSU. It takes like 30-60 minutes to drive from home to office and that's an hour of downtime even if it's a two minute transfer to a new PSU.

You're doing it wrong them. This is not a business that allows you to be hours away from it. If the datacenter doesn't have a room or something cheap/free for people colocating servers there, maybe you should move office closer (but i think you leased office for 3 years or something like that)

Anyway, power supplies don't fail that often. If it happens, replace within 1-2 hours and send emails to those guys saying that broken hardware was replaced.. if you feel like, you can give them a 5-10% off next month, let's say because they won't have 99.5% uptime or whatever you promise.

[shovenose]

Re: Custom Server Power Distribution Supply

IT. DOES. NOT. MATTER.

If you promise something to the buyers, you have to keep your word.

You don't have to promise 10 minute replacements, for budget dedicated servers it's quite common to have 1 hour hardware replacement or even worse.

But to do that, YOU HAVE TO HAVE SPARE PARTS AVAILABLE. What are you going to do otherwise, order another psu at Digikey and wait 2-3 days and receive it?

Same with hard drives or memory - 1 out of 20-30 drives will eventually fail. Some people will probably ask you to replace hard drive just at the sign of smart errors.. you need a few hard drives and memory sticks available all the time. Can't wait to have drives shipped from newegg or whatever.




You're doing it wrong them. This is not a business that allows you to be hours away from it. If the datacenter doesn't have a room or something cheap/free for people colocating servers there, maybe you should move office closer (but i think you leased office for 3 years or something like that)

Anyway, power supplies don't fail that often. If it happens, replace within 1-2 hours and send emails to those guys saying that broken hardware was replaced.. if you feel like, you can give them a 5-10% off next month, let's say because they won't have 99.5% uptime or whatever you promise.

I am not out to scam or mislead customers. But okay, I guess the best value in west coast dedicated servers is not happening. You're welcome!

[goontron]

Re: Custom Server Power Distribution Supply

original post got by thunderbird:

Here is the message that has just been posted:
***************

---Quote (Originally by mariushm)---
IT. DOES. NOT. MATTER.

If you promise something to the buyers, you have to keep your word.

You don't have to promise 10 minute replacements, for budget dedicated servers it's quite common to have 1 hour hardware replacement or even worse.

But to do that, YOU HAVE TO HAVE SPARE PARTS AVAILABLE. What are you going to do otherwise, order another psu at Digikey and wait 2-3 days and receive it?

Same with hard drives or memory - 1 out of 20-30 drives will eventually fail. Some people will probably ask you to replace hard drive just at the sign of smart errors.. you need a few hard drives and memory sticks available all the time. Can't wait to have drives shipped from newegg or whatever.




You're doing it wrong them. This is not a business that allows you to be hours away from it. If the datacenter doesn't have a room or something cheap/free for people colocating servers there, maybe you should move office closer (but i think you leased office for 3 years or something like that)

Anyway, power supplies don't fail that often. If it happens, replace within 1-2 hours and send emails to those guys saying that broken hardware was replaced.. if you feel like, you can give them a 5-10% off next month, let's say because they won't have 99.5% uptime or whatever you promise.
---End Quote---

I am not HOURS away from it. I'm under an hour away from it worst case scenario during traffic time from home.

Oh, and for these servers, office=datacenter. The business (read: expensive) servers would be real rackmount equipment at HE Fremont2 (not the one with power issues).

Can you focus less on my business and more on custom power solutions. After all, that is the purpose of this thread. Or would you rather I not do dedicated servers and simply push my "Cloud Server" product :P Higher margins for my anyway so you know what, problem solved.

I'm not angry at you; I'm angry at the fact that I can't even ask a legitmate question on the very forum that would be BEST qualified and has the MOST COMPETENT people I know of of any forum, without getting chewed out.

If I were not me you would have said this was a great idea, but because "it's shovenose, it must be fucking retarded" we did not get anywhere.

I was trying to be past this.
Gawd, I should just get my name changed, move to a different country, and rejoin, and everything would be fine.

I guess thousands of posts mean nothing. Thankfully I will be very busy with my new business (yeah, not ShoveHost, that is being "acquired" by my new company onto brand new, fully owned, locally hosted, expertly managed hardware)...

And my main shared hosting server hasn't had any outage in a long time and the last one was because the datacenter I'm with in San Diego moved my server to a different rack)...

So obviously I'm not the stupid incompetent fuck everybody thinks I am.
/endrant
***************

how old are you again?

[Stefan Payne]

Re: Custom Server Power Distribution Supply

I am not out to scam or mislead customers. But okay, I guess the best value in west coast dedicated servers is not happening. You're welcome!

Why aren't you aknowledge the postings in this thread?
It's not like there are any evil people here who mean you harm or don't want you to do what you are planning to do. It's quite the opposite.

So the best thing to do is to read the postings in this thread again, think about what you're doing, reevaluate it and come up with a better plan. And not trying to 'run away' in whatever way you are doing right now...

[shovenose]

Re: Custom Server Power Distribution Supply

Why aren't you aknowledge the postings in this thread?
It's not like there are any evil people here who mean you harm or don't want you to do what you are planning to do. It's quite the opposite.

So the best thing to do is to read the postings in this thread again, think about what you're doing, reevaluate it and come up with a better plan. And not trying to 'run away' in whatever way you are doing right now...

Some of the posts and suggestions in this thread are well thought out, smart, sensible, and helpful. But it doesn't matter.

[mariushm]

Re: Custom Server Power Distribution Supply

I am not out to scam or mislead customers. But okay, I guess the best value in west coast dedicated servers is not happening. You're welcome!

I honestly don't understand how you drew this conclusion from my messages.

I did not say any of that, I was just trying to give you helpful advice.

I simply stated that most companies have an employee physically in the datacenter so that it could handle server reboots, replacing some faulty ram within minutes, stuff that's easy to be done even by some paper pusher.

Some datacenters have their own staff available and are willing to sign a contract with you and then you have one of their guys available in case there's something easy to do, like rebooting a server, adding a stick of memory, replacing a stick etc, and they usually charge something like 15$ for 30 minutes with a few free minutes each month.

You're going to compete with a lot of companies that also offer budget servers and they're going to have promises in their sales pages that are easy to accomplish because they already have the staff employed and they can use this staff for free basically, when they're not busy handling tickets for premium customers.

You may be tempted to offer the same conditions those companies have, but that's not going to work long term if you don't actually have someone all the time where your servers are. For example, can't promise 99.9% uptime, if you're one hour away from server.

If you're going to say on the sales page for these budget servers something like "Hardware replacements within 4 hours" or "99.5% uptime guaranteed" you've covered your ass and you'll be fine even if you're not physically by the servers or you don't have staff there. However, you're still going to keep your promise and replace hardware in that reasonable 4 hours, which isn't going to happen if you don't have spare parts. From your messages, maybe I got the wrong idea that you don't want to have spare parts, to save money... that's not going to work.


A lot of companies also lease their servers from Dell and others, they simply pay 20$ a month for 3 years or something like that and lease 200-500 servers at the same time. With such a purchase, you get good service contracts, they replace hardware the next day if it's faulty and so on. Companies keep a few servers as hot spares anyway, so they could just pull out the hard drive and stick it in another server and user will be up within minutes and the faulty server will be serviced/replaced the next day by Dell/others.

That's how a lot of companies can afford those i3 servers and charge under 100$.. they pay for them in less than 2 years. Once they're old technologically and they're paid, they can be sold to people for 50$ a month or whatever budget prices are, because the cost is basically just rack space and electricity and bandwith, now that 20$ a month that was going to Dell is going into their pockets.

When you're small, you buy hardware outright only if it really makes sense for you, and this would be if it's really cheaper than leasing servers and paying for them for several years.
At about 150$ a server with that mb+cpu+ram+hdd+ psu shared by 8-10 systems, it's probably cheaper than actual servers.. if you don't keep count of work hours needed to make the case, and that datacenter staff may not handle your custom servers... so it may be worth it.

You have to do the math, see how much rack space costs, how much ip cost (do they give you a limited ip count per rack etc etc), see how much you're left after paying for bandwidth and rack space, then figure out how fast you're going to recover your money.

You have a big investment from the start (about 2000$ I guess) for a 3-4U custom server with 8-10 such itx systems + a 8-16 port switch if needed, and if you charge them too little, you're only going to recover that money in 6 months or so.

[shovenose]

Re: Custom Server Power Distribution Supply

I won't be paying for rack space or power.
Of course I would have spare parts.
99.9% NETWORK and POWER uptime guarantee. 6 hour hardware replacement SLA. Easy.

[mariushm]

Re: Custom Server Power Distribution Supply

Who pays for electricity then?

It adds up, it's a cost you have to keep in mind. Looking at this, it's about $0.15 for 1kWh, so 10 servers using 50w each will cost you about $1.5 a day in electricity.

Then you have to think about air conditioning or cooling the place down. Yes, the servers each uses little power, but the heatsinks of each of those servers will be hot so they'll heat the room.

The power supply is also only 80-85% efficient so those 50-60w dissipated as heat will heat up the room as well.. that will also cost you some money, for electricity to cool the place down.
If you have electricity included in the lease of the place or something like that, you have to check those contracts, because you probably have some limits regarding how much you can use each month.

And then you would also have to check how well the place is wired .. you guys have 110v 16A circuits or something like that, which is low.

If you want to set up a whole rack with 50w servers, you can't just plug them all in a single 1500w max socket, make sure your wiring is up to par in the place where you plan to set up your "racks".