Putting more than one computer in a pine box

[fivemack]

A case and PSU from a reputable manufacturer costs about £65; this is more than 15% the cost of an Ivy Bridge compute node.

Each such node takes about 100W, so I would hope to be able to power four of them from a 650W PSU of the kind that costs £55 from a reputable manufacturer. Are there reasonable ways to power several standard mATX motherboards from a single chunky PSU?

[xilman]

Originally Posted by fivemack

A case and PSU from a reputable manufacturer costs about £65; this is more than 15% the cost of an Ivy Bridge compute node.

Each such node takes about 100W, so I would hope to be able to power four of them from a 650W PSU of the kind that costs £55 from a reputable manufacturer. Are there reasonable ways to power several standard mATX motherboards from a single chunky PSU?

Yes.

I worked on a system which had 7 Linux microATX servers and a GbE switch all packed into a 2U case. (Keeping it cool was an interesting exercise!)

I don't have the details to hand but I'll try to look them out.

Paul

[TObject]

Also take a look at Supermicro Twin Solutions.

[kladner]

Originally Posted by fivemack

.....Are there reasonable ways to power several standard mATX motherboards from a single chunky PSU?

A typical PSU has only one set of motherboard connectors. Do you plan on building your own wiring harness? I take it that this would be dedicated to CPU work only, so the display adapter(s) could be fairly low in power demand.

I only mention this because I found out the hard way that 650 watts was not enough for a Phenom II x6, a GTX 460, AND a GTX 570.

[fivemack]

Originally Posted by kladner

A typical PSU has only one set of motherboard connectors. Do you plan on building your own wiring harness?

I was rather hoping that an adaptor from 24-pin ATA to 2x24-pin ATA was a standard item of commerce - though thinking about it I'm not quite sure what I'd have to do to get the PWR_OK sequencing right, that looks as if the motherboard and the PSU do a handshake (PS_ON goes down, a little later PWR_OK goes up) and I'm not sure whether there's a problem if I pull PS_ON low and PWR_OK high.

I take it that this would be dedicated to CPU work only, so the display adapter(s) could be fairly low in power demand.

Yes, I would intend to use just the on-chip GPU, and probably only plug in a screen when installing the OS.

[fivemack]

Originally Posted by TObject

Also take a look at Supermicro Twin Solutions.

I'm not sure those fit remotely within my budget, they seem to be custom motherboards and to require Xeons.

[sdbardwick]

Originally Posted by fivemack

I was rather hoping that an adaptor from 24-pin ATA to 2x24-pin ATA was a standard item of commerce - though thinking about it I'm not quite sure what I'd have to do to get the PWR_OK sequencing right, that looks as if the motherboard and the PSU do a handshake (PS_ON goes down, a little later PWR_OK goes up) and I'm not sure whether there's a problem if I pull PS_ON low and PWR_OK high.

24 pin ATX splitters exist (one example here); IIRC they only connect green power on cable to one motherboard, which becomes the master (power it off and the PSU shuts down).
EDIT: The one pictured has the cable connected to both plugs, so maybe you can shut down from either computer.

[TObject]

Originally Posted by fivemack

I'm not sure those fit remotely within my budget, they seem to be custom motherboards and to require Xeons.

It is just something off-the-shelf you can buy instead of making your own. Making your own is more fun, though.

[c10ck3r]

Originally Posted by TObject

It is just something off-the-shelf you can buy instead of making your own. Making your own is more fun, though.

I suggest oak. It tends to be much more durable than pine :P

[xilman]

Originally Posted by c10ck3r

I suggest oak. It tends to be much more durable than pine :P

Given that the average computer has a shelf-life only slightly greater than a Ratner's prawn sandwich(*), I suggest pine on the grounds that it's markedly cheaper.

Paul

(*) UK readers should know what I mean by that.