Mini-cluster power (Avoton)

[Risar]

Reading through the various 'cluster in a box' posts out there, including the one on STH and one topic that nobody seems to have solved is making the power situation a bit 'cleaner'. Specifically not having tons of power bricks to deal with. Since what I'm looking to do is have a mobile 4-6+ node box I'm curious about options others may be aware of.

Does anyone make a PSU that comes wired for multi-node ?
Is there some way to minimize the brick footprint (eg not 1:1) that I'm unaware of ?

 

[PigLover]

The supermicro avoton boards will run on 12v input. No need for multiple bricks, etc. Just get a single stable 12v supply and run them all off of it.

 

[Hanss]

Reading through the various 'cluster in a box' posts out there, including the one on STH and one topic that nobody seems to have solved is making the power situation a bit 'cleaner'. Specifically not having tons of power bricks to deal with. Since what I'm looking to do is have a mobile 4-6+ node box I'm curious about options others may be aware of.

Does anyone make a PSU that comes wired for multi-node ?
Is there some way to minimize the brick footprint (eg not 1:1) that I'm unaware of ?

A fair comment.
Having a power brick Pout=(Pmobo+ Pram+ Phdd...)x(4-6+) +20% (reserve) power output - you can achieve.
But this brick can be heated!
But its output connector should transmit 30-50 amps!!!

see USER’S MANUAL
Note 1:
The A1SAi and A1SRi Series motherboard alternatively supports a 4-pin 12V DC input power supply for embedded applications. The 12VDC input is limited to 12A by design. It provides up to 144W power input to the motherboard. Please keep onboard power use within the power limits specified above. Over-current DC power use may cause damage to the motherboard!

 

[mackle]

I would think that it would be reasonably difficult to get to 144W through the motherboard, given their very low power consumption and form factor. Even if you had a discrete GPU that pulled the max rated 75w from the PCIe slot you'd struggle to get above 110, from what I've seen in the benches.

 

[Hanss]

I would think that it would be reasonably difficult to get to 144W through the motherboard, given their very low power consumption and form factor. Even if you had a discrete GPU that pulled the max rated 75w from the PCIe slot you'd struggle to get above 110, from what I've seen in the benches.

I agree.
The requirement that at 144/110 watts protection tripped.
But if the brick will be designed on the two boards, the protection triggered only with 288/220 watts. Etc.
Thus Any board may be damaged.

 

[Risar]

The board I'm looking at is the Asrock C2750D4i

There will be no graphics or add-on cards, as this will be headless and managed via IPMI. CPU, RAM and a small boot drive are the only components each node will need. I'm more wondering if someone has a solution that doesnt take up as much space and such as the power brick-per-node solution does.

 

[Philip Mansfield]

I've just signed up to post in here, as I'm currently planning a similar thing. I've just taken delivery of a C2750D4I today and have set it up in a standard m-ITX case for the time being.

My intention is get a fairly beefy ATX PSU and then for each C2750D4I I'll get a 80w (or thereabouts) Pico PSU, which should be fine for the board, and an SSD. The plan then is to wire the 12v input on the Pico PSU into a 12v molex connector from the ATX PSU.

I reckon I can run 3 of the C2750D4I boards from each of the 12v rails on the ATX PSU, but to be honest, 3 of them should be enough for what I need.

 

[TuxDude]

Whether using MB's that support 12V power inputs directly, or PicoPSU's per board, I would probably try to base it off of a rack-mount hot-swap PSU instead of a big desktop one. For instance, the SuperMicro PWS-920P-1R I've got in my 4U puts out 75A @ 12V and then it is the power distribution board's job to convert down to the other voltages needed in the system.

Bonus points if you can build a power management system out of something like a raspberry-pi to have full remote control to power on/off individual cluster nodes - the pi (or other similar embedded board) could run off the 4A of 5V standby power that that PSU also puts out, and for even more bonus points you could tap into the SMBUS pins for full remote power monitoring.

 

[Patriot]

Whether using MB's that support 12V power inputs directly, or PicoPSU's per board, I would probably try to base it off of a rack-mount hot-swap PSU instead of a big desktop one. For instance, the SuperMicro PWS-920P-1R I've got in my 4U puts out 75A @ 12V and then it is the power distribution board's job to convert down to the other voltages needed in the system.

Bonus points if you can build a power management system out of something like a raspberry-pi to have full remote control to power on/off individual cluster nodes - the pi (or other similar embedded board) could run off the 4A of 5V standby power that that PSU also puts out, and for even more bonus points you could tap into the SMBUS pins for full remote power monitoring.

High amperage pi controlled driver circuit... hmmm

 

[TuxDude]

High amperage pi controlled driver circuit... hmmm

I was thinking the simple way to do it would be using PicoPSU's, and just use GPIO pins connected to the atx power-switch headers on the motherboards to be able to remote control power signals.

Far more complicated if you have to control the high amperage switching from the pi - still possible using relays and such but a lot more complicated than just connecting a GPIO to a power-button-header.

 

[Patriot]

I was thinking the simple way to do it would be using PicoPSU's, and just use GPIO pins connected to the atx power-switch headers on the motherboards to be able to remote control power signals.

Far more complicated if you have to control the high amperage switching from the pi - still possible using relays and such but a lot more complicated than just connecting a GPIO to a power-button-header.

Ooooou I see now. Totally more doable.

 

[PigLover]

Wow...is this a thread about making simple things as hard as they can be?

You don't need any Pi-based power control. The board you are proposing to use already has IPMI with remote power control. You'll have to connected the IPMI lan but - presto - full remote power control

Building the Pi based power control would be fun - but completely unnecessary.

 

[Risar]

My intention is get a fairly beefy ATX PSU and then for each C2750D4I I'll get a 80w (or thereabouts) Pico PSU, which should be fine for the board, and an SSD. The plan then is to wire the 12v input on the Pico PSU into a 12v molex connector from the ATX PSU.

This seems like the most appealing approach. The thing I'm trying to figure is how to actually do the wiring (power is not my strong suit).

The Asrock looks to have a 24Pin ATX but should work with the 20Pin ATX picoPSU-80-WI-32 in specific. If you combined that with a PSU that had multiple 4Pin (or 4+4 ?) connectors I assume that would work. Eg: EVGA SuperNOVA 750 G2 220-G2-0750-XR 750W ATX12V / EPS12V SLI Ready 80 PLUS GOLD Certified Full Modular Power Supply Intel 4th Gen CPU Compatible 10 Year Warranty - Newegg.com

 

[Philip Mansfield]

For the wiring, I'll buy a DC power splitter cable: BW 1 to 8 Way DC Power Splitter CCTV for Security: Amazon.co.uk: Electronics cut off the tails and crimp on some pins for the molex connector.

That PSU should be OK, but personally, I'm going for one that has two 12v rails, as I'll want to power some other stuff inside the chassis.

 

[MiniKnight]

Subscribed to this thread. I think the multi machine single PSU thing is the way to go for these low power systems. It makes me cringe when I see C2750/C2758 systems being run off of 500w PSUs.

 

[Hanss]

This seems like the most appealing approach. The thing I'm trying to figure is how to actually do the wiring (power is not my strong suit).

The Asrock looks to have a 24Pin ATX but should work with the 20Pin ATX picoPSU-80-WI-32 in specific. If you combined that with a PSU that had multiple 4Pin (or 4+4 ?) connectors I assume that would work. Eg: EVGA SuperNOVA 750 G2 220-G2-0750-XR 750W ATX12V / EPS12V SLI Ready 80 PLUS GOLD Certified Full Modular Power Supply Intel 4th Gen CPU Compatible 10 Year Warranty - Newegg.com

HRPG-450-12 - 450W, 12V single output with PFC function

 

[Risar]

HRPG-450-12 - 450W, 12V single output with PFC function

I've seen a few folks post this type of PSU before, but I'm unfamiliar with it. What are the benefits of using this type and having to wire it ? (Presumably vs using a single well-powered modular ATX PSU) ?

 

[PigLover]

If I were building a stack of Avoton boards into a mini-cluster I'd use the SM board with 12v inputs and an industrial 12v PSU like the example posted by Hanss.

I'd prefer this over using an ATX supply because it's a simpler design. Lots of un-needed stuff in the ATX supply to do 5v, etc. Fan designs that expect to be mounted in a case with a specific airflow, etc. Plus the power control is wrong...either one MB is in control or you have to fake it out with a jumper on the 24 pin connector.

But that's just me. The approach that uses an ATX supply will work fine...

 

[Philip Mansfield]

If I were building a stack of Avoton boards into a mini-cluster I'd use the SM board with 12v inputs and an industrial 12v PSU like the example posted by Hanss.

I'd prefer this over using an ATX supply because it's a simpler design. Lots of un-needed stuff in the ATX supply to do 5v, etc. Fan designs that expect to be mounted in a case with a specific airflow, etc. Plus the power control is wrong...either one MB is in control or you have to fake it out with a jumper on the 24 pin connector.

But that's just me. The approach that uses an ATX supply will work fine...

I intend to run 3 of the ASRock boards in a PC chassis from 12v, along with a 4th system powered by the ATX connector on the PSU. The 4th system will be a NAS, so will be making proper use of the ATX PSU.

If I was only going to be running Avoton boards, then yes, a proper 12v power supply would be preferred.

Hopefully people will post a few build logs and details as they progress with them

 

[Risar]

I'd use the SM board with 12v inputs and an industrial 12v PSU like the example posted by Hanss.

I'd prefer this over using an ATX supply because it's a simpler design.

I dunno how its simpler, but again I'm not familiar with using these types of power supplies. Maybe someone can ELI5 how I'd wire this, because Google isnt turning up much and from my perspective although its probably "proper" it seems like a PITA.

Lots of un-needed stuff in the ATX supply to do 5v, etc. Fan designs that expect to be mounted in a case with a specific airflow, etc. Plus the power control is wrong...either one MB is in control or you have to fake it out with a jumper on the 24 pin connector.

No argument here, though how this would work depends on the bios and ipmi options you leverage. The PSU should just draw the power it needs even if its always in an "on" state.