George's dream build

[Madpoo]

Originally Posted by endless mike

I think with some cable management, I can get an eighth board in place above the power supply. There might end up being a heat issue though.

Given that heat rises, I wonder if a fan mounted on the top of the case (if it has that option, I couldn't tell from the pic) would be a good idea.

With the rear mounted fan, it seems like incoming air would come in from the front (or side also, if it's there's a side-fan option).

Meaning those couple of boards by the exhaust fan are passing all of the heated air from every other system in the case when it's closed up?

I was just trying to puzzle through what the best air flow options would be to make sure there aren't any obvious hot spots.

[endless mike]

Had my first issue between one and two days ago based on last check in date.

Note the melted white connector and wire insulation.

The wires on the plug one the right is pulled out just a bit from the connections; wonder if that's the cause? Except no melted plastic there.

Only one of three boards powered off this adapter went down, the other two were still happily double checking away.

The plug was tucked away behind the mother board tray with no air movement along with most of the rest of the wiring.

[kladner]

I have PCIe VGA power connectors that look similar. In that case, poor contact with eroded pins on the GPU was the apparent culprit.

[LaurV]

Yes, the reason is bad contacts at the white connector, maybe the blades not spring enough, etc. The black jacks has nothing to do with it. You can however improve the contacts at the jacks too, if you first add some tin to those wires. The loose copper wires in the green sockets look very unsafe for me, they can make shorts, etc. Usually I make them "rigid" loading them with tin first, using a soldering iron, make them look like small nails/rivets, then put them into the sockets, and tighten the screws tight. If you melt the tin right, then it goes inside of the insulated part too, and the copper will not break when you bend them or when you tighten the screw.

For the white connectors, if they have elastic blades inside, they lose their elasticity when the temperature raise, this is a common failure, especially for cheap, low quality "made in china" stuff.

[srow7]

I built a 4 board system using H110M-ITX and I5-6500.
Using stock clocks and voltages.
Getting similar benchmarks as post #103.
Temps 60-62C.
285W at wall
open air, not going to use a case.
about $1600
current config = DC, 4 cores/worker
getting matching residues, earned cat1 DC status.
differences from other builds:
1. used fedora linux, smooth install
2. used ATX cable splitters instead of picopsu.

lessons learned:
I dont recommend atx cable splitters for more than 4 boards, cables get out of control.
I will try picopsu next time.
very pleased with results

[Mark Rose]

Whelp, I just ordered me a cluster: four i5-6600's with 32 GB DDR4-2133 each. I found Gigabyte GA-H100M-A motherboards for $30, so it wasn't worth getting the fancy ASRock boards at $92.50. I decided to up the CPU to make the cluster more useful for other applications and to improve resale value: nobody wants a low end chip (the i5-6600 is the same speed as a stock clock i5-6600K). Going with 32 GB was only 3 times the cost of 8 GB, plus I won't have to worry about getting rid of 4 GB sticks in the future. They're all going to be powered by a single EVGA 210-GQ-0650-V1 650W 80Plus Gold using ATX splitters. The splitters won't arrive until I'm back from holiday, so pictures will have to wait until after then. I already have all the needed networking stuff.

The total cost is about $2250 or about $1725 US. Had I got with i5-6400 and 8 GB, it would have been $1625 or $1250 US.

[Prime95]

Originally Posted by srow7

I built a 4 board system using H110M-ITX and I5-6500.

Originally Posted by Mark Rose

Whelp, I just ordered me a cluster: four i5-6600's with 32 GB DDR4-2133 each.

Welcome to the cluster computing club! Warning: It's addictive -- I'm itching to add more CPUs...

[Mark Rose]

Originally Posted by Prime95

Welcome to the cluster computing club! Warning: It's addictive -- I'm itching to add more CPUs...

Haha. I'm limiting myself to what a single power supply can do.

I bought all the components, except the splitters, on sale at Newegg. The sale has a limit of 5. It's tempting to buy one more machine... I do need a new desktop... hmm...


Edit: It happened.

[Mark Rose]

For anyone doing these builds, get a power supply with a 4+4 ATX power connector. I'm glad I did. I initially was using three splitters off a single half of the 4+4 connector, and the cable was getting quite warm using 4 i5-6600 65 watt CPUs. It was easily 15°C over ambient measured with an infrared thermometer.

So I ditched one of the splitters and now run two boards each off each half of the 4+4 connector. The pin-out is identical for both halves, and the connectors will mate. Everything stays comfortably cool now.

I've also not felt any heating issues with the 24 pin cables being split 4 ways.

[diep]

In general spoken most PSU's are most efficient if total power consumption is 50% of what the PSU can deliver.

This is especially true for the better ones, the 80+ ones not to mention the Gold ones. At cheaper PSU's it's usually not luxury to use just a part of what they can deliver as they break down quickly if they need to sustained deliver nearby 100% of their max output.

So if your expected rig is gonna eat expected say 250 watt, then buying an expensive psu that's delivering 800+ watt is not so much needed.

Efficiency when using far UNDER 50% of total output is dramatic inefficient compared to efficiency around the 50% mark.

For the Xeon L5420 nodes i had built (8 real cores a box) here i had therefore ordered a bunch of gold rated psu's of 350-400 watt which were not overly expensive compared to the 200 euro a piece prices of the heavier PSU's. For the nodes equipped with Tesla/GTX580 i'm using Corsair 860 PSU. Yet that might be overkill for most here.

Wouldn't buy such expensive ones again if i would face the same decision. Would settle for 80+ bronze probably then for the heavy PSU's.

[masser]

Given the power/space limitiations, what kind of GPUs could you add to these rigs?