Small 100W server build log [part2] - Overclock.net

dragosmp · 06-28-08

A few months ago I was writing a thread on a small server that was in construction. Here's the post as that time:

Quote:

Originally Posted by Part1 of teh server log

Hey,

I am working on building for some time now a case for a really tiny server. What I expect him to do:
- file server: lots of space, data security
- all around connectivity
- low consumption, low noise
- no wires (except plug) and small.

Tech solutions:

- 2x500GB HDDs (brand unknown for now) in RAID 1
- connectivity Wi-FI (n draft), Bluetooth, eventually remote control TT Mozart style
- sempron 2800+ CPU passive, AMD 690G chipset, fans piloted by a electronic card I made in function of temperature (max supported =2 fans)
- home made wooden box with a metal frame

It's not exactly in chronological order as I've began it 2 months ago working now and then, but it's surely the logical order in which should have been done.

The main problem is heat - I have chose everything to enter a 150-170W power envelope and a minuscule volume.

The shopping chart:

Bought a cheapo 480W PSU (10$) that should provide 200w without overheating, an ASUS M2N-VM 690G, and reused 2GB of Ballistix DDR667, a 8GB old HDD and a 2800 sempron I had laying around.

The PSU:

Any ATX PSU is far to big for what I intended so I simply took out the PSU PCB out of the iron case; you'd be surprised how much space is wasted.

After this I bend the radiators to occupy a smaller volume - this doesn't change anything in their cooling abilities.

I removed the 120mm fan as there wasn't any room for it so the PSU became passive and as a result dead silent.

After this diet, the PSU is just the size of two cigarette packs one on top of the other - and it works (tested and retested every step of the way)

Sometime later, after mounting everything in the small case I built (details below) I realized the wires for the ATX 24 pin connector were too long and filling literally every cubic inch of air available in the case. They lost some weight also, some 8cm from the 15cm in total(4" from say 8" for the imperial units) in total to be just as long as they have to barely reach the ATX plug in the mobo.

THE CASE

The principle of the case is in the picture below. It has to be just a bit taller than a PCI card, and sufficiently wide as to receive a 25x25cm µATX board.

Since the server needed to be really small, silent and more than anything cost effective it seemed obvious from the get-go that I had to build it myself. I had no experience in welding, but fortunately I have friends, beer and jokes in my schedule, so a total of 3 guys were enough to cut some iron plates that were to form the skeleton, weld them together to have the frame and cut the wood plates that were to silence the beast inside.

And a lesson to others reading and living in a flat: always a keep good relationship with the neighbors, 'cause they can get really pissed when hearing an electric drill at 10 p.m. If you have invited them to you barbecue the other day, they'd be easier to accept these phonic aggressions that are inevitable when building something.

I'm a highly mathematical person, I like to calculate everything in the smallest of details, the angles, distances so that there is a perfect fit. It just so happens that from the start of the project I supposed the PSU rad and the CPU rad would be face-to-face and touching.
Obviously, the hours of thorough calculations were brought to nothing when we realized that we forgot to take into consideration the effective thickness of the wooden plates. They're only 4mm thick, but enough to make us miss the overall inside height of the case by 5mm (more or less). This in turns meant some more modifying of the PSU's radiators...

Cooling as it was originally thought

The idea was that a 80mm fan I had laying around to pull hot air from the area that contains the radiators of the PSU/CPU/NB . It's sorta like a tunnel where the fresh air enters thru somewhere (not exactly defined in a first approach), is being routed in one end of the box, traverses the radiators that are packed together and is being pulled outside by the 80mm silent fan, much like this picture below:

I figured I'll see where to make the intake hole for the air to get in as the case is in wood afterall and holes can be made easily. The idea was the hole to be where the eventual hotspot is.

The assembly

Well, having worked for two months I was burning to see all the stuff in the case and install a Win2000 SP3 copy I have since a while ago when my main rig wasn't powerful enough to handle the "enormous memory requirements of windows XP".

BTW, Vista a memory hog? When XP appeared, the 128MB of ram became highly insufficient. 256 minimum for XP. XP SP2 upped to 512 minimum with 1GB to be smooth. In total there was a 4x multiply in ram needs over XP's lifetime. Vista say it needs 4GB to be smooth, so why all the hustle? And what did XP bring, some more eye candy vs Win2000. Same old story...

Now in the assembly, as stated earlier, I quickly found out the ATX cables have to be put on a diet. I welded for over 3 hours, since I'm not very good. I didn't want to make any mistake, as it would fry the mobo 'cause that would have sucked.

Windows install

All smooth, nothing to see

Except the fact it was installed in open-air (aka no case) because I needed a PATA cable connected for the DVD-ROM; the server won't have any optical unit.
A small issue that wasn't so obvious at the beginning was the lack of drivers for the 690G chipset in Windows 2000. Some XP drivers worked, others didn't...

Burning tests

Now the fun part: cooling design. Remember I have only one fan that is pulling air. From where? Dunno, probably from the hinges of the wooden case. The only purpose of this test was to identify the major heat sources. Anyway, after 20mn of 100% CPU it went at 47°C and still rising. Shutdown and back to the drawing board.

There seemed obvious 2 hotspots:

The CPU was the hottest thing around, the PSU rads didn't seem to hot. In the lower floor where the HDDs are isolated (in this test it is actually only one HDD) it heated up a bit too.

Advice time

Now there are ways to tackle this issue and I thought of two scenarios pictured below:
1. Put a 80 mm intake fan in the right, output in the left and venting holes to ventilate the hdd are

2. Put a 80 mm output fan in the right, seal on the left and in the HDD bay area make a hole below the HDDs for the air intake, and make a hole in the left, so that the warm air rises and further cools the array of radiators; here I suppose the HDDs will not overheat since I suppose I'm getting Caviar GPs:

What do you think of the build, the story, the server, and more importantly, how do you see the cooling system to be as efficient as possible?

[Eventually] The cooling solution chosen was:

I have tried a compromise to cool both the HDDs and the upper electronics part. This is a done deal, the mini-server works.

Observations on the version 1.0 of the case:

From the picture above it's not easy to realize, but the ATX wires obstruct the airflow, they are perpendicular to the flow.
The sempron 2800 is hot. Since it doesn't support C'nQ it's at 1600MHz and 1.35V all the time (~60W dissipation)
The 480W modded PSU works fine. However the rads on the PSU are hot. This leads me to thing the efficiency of the 480W PSU @150W is horrendous.
The HDDs are quite warm: 45-47°C. In my room there is around 25°C which doesn't help either, but the 20°C delta is quite a lot.
These heat outputs have forced the choice of two fans to cool the thing. Despite this, the CPU is @57°C, mobo @43°C and HDDs@47°C
The fans run @1000 rpm, but the siffle of the air is noticeable.

Bottom line: for a first version it works pretty well, but I should do better.

The version 2.0 of the case:

From this version I planned a few improvements:

Remove the ATX PSU from the case. Power the server with a laptop adapter and a 12VDC/ATX converter. These things are limited to 120W thus this is the new power consumption limit of the server.
The case is quite tall, I would like to reduce its height. Removing the PSU will help do just that.
HDD's will be moved in the place of the PSU, thus teh whole lower compartiment will disappear.
Replacing the Sempron 2800 that does not support C'nQ with a CPU that does support C'nQ, thus can be underclocked @800MHz. This alows me to fit the power envelope.

The idea is to replace the design of the V1.0 with the V2.0:

V1.0:

With V2.0:

It's a so much simpler design that it will probably allow me to work in only one fan at significantly lower temperatures, or at least in two fans at lower temps

The 110W power consumption limitation and components chosen for V2.0

Tech solution:

The tech solution chosen is to power the server with a laptop plug + a 12VDC-to-ATX adapter. Here's what shinji2k linked me on another thread (I made lots of them): http://www.mini-box.com/picoPSU-120-power-kit

From yet another thread I've gathered some power consumption figures that I've listed below. They are rough estimation for generic components, not an exact figure. The exact figure is pointless IMHO even if it were possible to be measured, because it depends on the specific component used.

Power consumption of all components except the CPU

- midrange ATX mobo 38W
- µATX mobo 25W (figure from DuckieHo's 780G)
- 3.5" HDD 7200rpm 15W peak - 11W load (credit DuckieHo)
- OLD 3.5" HDD 7200rpm 30W peak - 12W load (source)
- 3.5" HDD 5400rpm 12W (www.silentpcreview.com)
- DVD+-RW 27W
- 1x stick DDR2 3.5 to 4.5W
- usb 2.5W (peak power - credit DuckieHo)
- firewire 7w
- fan 120mm 4W
- fan 80mm 1w

The CPU:

The CPU wattage depends on what you want to use. I have chosen two examples:
- Athlon X2 4400 AM2 65nm @800MHz @0.85V 9W
- Phenom 9550 @1000MHz @1.0V 30W

I have chosen to underclock both CPUs (using the OC CPU button from the PSU calculator lite) because there is little need of high-speed CPUs on low power media center/server PCs.

My server will kinda be a jack of all trades, it will have to play the role of a media center PC for esample. That's why I plan on sticking to AMD: 780G, nV8300 or 790GX aka hardware accelerated HD content. Intel doesn't have it, thus it can't possibly work with the CPUs underclocked.

A possibility to use Intel hardware would be an ATOM/underclocked Celeron+HD3450 for the HD playback, but the usage of a discrete VID card implies a taller case. It would make sense only in the advent of using something like the ATI All-in-wonder HD3650 since it also has a TV Tuner and superbe quality. I keep these options for a V3.0 of the server

What do you say? Looking forward to suggestions

and to rep+ the helpers as usual.

D.

S2000_Skyline12 · 4 Weeks Ago

Damn man, that sounds sick

I would get that All in Wonder and make it a media center along with a media/general file server, and putting in a laptop optical (if it's even possible) or a external DVD drive wouldn't hurt though. Would make it a bit more flexible for the media idea along with being a server. I would also not go with that under powered Celeron for HD playback idea, wouldn't fare out too well imo but that's just me.

Sempron 2800+
AiW 3650
Optical (external)
1TB

That would be awesome

dragosmp · 4 Weeks Ago

You posted there a couple of great ideas, first the AiW card. Frankly I had completely forgot of this. Now the problem is kinda like this: WHERE?

It looks great, just that it's full-PCIe and the height of the card would be quite important. Anyhow, for the version 2.0 of the server I haven't started the build yet, but I have to keep myself in a 120W power envelope and this would probably eat half right out of the box.

As a motherboard, I have found what is (yet to be launched) the ONLY mini-ITX mobo with a PCIe slot:

details here

The CPU: Well, I've managed to undervolt the Sempron 2800+ from 1.30V to 0.95 while keeping the clock at 1.6GHz (can't alter the multi, doesn't have C'nQ). This lowered the temps from 60-61° to 49-50°, massive 11°C bonus. Acording to the power calculator I've dropped it's TDP from 62W to 31W.

The HDD: I guess it will all depend on the place I've got. I'm hoping to have enough power in the 120W for the AiW (which became sort of priority) AND for a 3.5" HDD, but I doubt. A 320GB 2.5" HDD, or two of them in RAID-0 should fit in, but we'll see. I have a 6.4GB 2.5" HDD and I'll go with that for the testing for now.

Cheers!

S2000_Skyline12 · 4 Weeks Ago

Hmm, try the 'egg, Tiger or another good place like Amazon or something, they may have

dragosmp · 3 Weeks Ago

Update on the cooling part on the V1.0 of the server

Sempron undervolting: I've managed to drop the Vcore to 0.95V 2 weaks ago from 1.35V which obviously dropped the temps a lot, so I could run in one exhaust fan.

Cooling failure: this morning however the server shut-down due to overheating (65+°C), so I'm forced to mount back the second fan. Now the temps are much more reasonable 37-40°C; if I knew it makes such a difference...

Future projects

- getting a Arctic freezer 64
- buy industrial heat-pipes and design my own cooling system with the plate+rad from the AC64 and my heatpipes.

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Small 100W server build log [part2]

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