Balancing server power (speed) with power (watts)

by Simon St. Laurent

I've been thinking about building a small server for years, and getting closer to it now, but I'm trying to figure out how to avoid creating another vampire in my household.

At one point, I was running four computers here twenty-four hours a day in my office, and it greatly reduced the need to heat this room in the winter. My electric bills were impressive, even compared to the gas bills in my uninsulated house with an ancient furnace.

I've pushed those bills down over the years, replacing most of the computers with laptops and cutting out the servers in favor of appliances - first a SnapServer, then a Linksys network storage link, along with a few HP JetDirect boxes. The appliances still suck power, but it's a total of about 60 watts instead of the 500 their predecessors used. I leave an iMac up most of the time I'm here, though it does at least get turned off when I travel. Oh, and I replaced the furnace and insulated the house.

I'm at the point now where I'd like to have a server again, running programs that go beyond the file and print services that were easy to replace. Mapping and database services don't seem to come in prefab boxes, at least not cheap prefab boxes.

This leaves me with a problem. This server will have a lot of work to do for short periods of time and long stretches of complete idleness. Power management can help with some of this, turning off parts that aren't needed, but there's still either a significant power drain or a substantial delay when the system first gets pinged.

Options I've looked at include:

  • Trying to do this with a mini-ITX system that uses less power overall. My initial plans should fit within its capabilities, but I'm not nearly as certain over the long term.

  • Use parts designed for notebooks, like the Pentium M chips and the Intel 855 chipset. There aren't a lot of motherboards available for this, and it is more expensive, but I've been very fond of it in my notebooks. The chip's ability to select a speed (and power) based on use makes it very appealing, though more expensive per MHz.

  • Build a standard system, maybe with a less power-hungry chip, and hope power management tools are more effective and less intrusive than I remember them being.

Any suggestions for striking a balance on this are welcome. It seems like power consumption is an area that the server manufacturers have explored for higher-end blade systems, but not something that's come down to more ordinary box-building.

Oh, and I'd like it to be really quiet too.

Any suggestions for how to balance processing power with power consumption?


2004-12-07 20:55:27
Try a pug
I found these little boxes on Ebay, but you can also buy them direct
from the company for a premium.

Small, DC power supply, no fan, uses RAID and runs Linux internally,
which means it's hackable to run anything else, too.

2004-12-08 14:34:29
Mobile components
Hello, I think that the mobile components options will be a good solution.

The problem with the Pentium M is that the chip its mobos are very expensive. Because of that i think that a good solution will be the use of an Athlon XP Mobile processor, a 2200+ might cost about 100$ and a MicroATX SocketA mobo about 50$. You can also use the frecuency and voltage scaling mecanism... that processor eat about 35W at full load, but with frecuency scaling the processr will be running at 700Mhz most of the time, with a power cosumption of about... ¿15-20W?

Other things you can do to reduce power cosumption are:
- You might not put an optical drive in the server, you can du all what you want throught the LAN.

- You might use an old VGA, you don´t need a GF5 :), not even a TNT... an ATI Rage IIC or a S3 Virge would be most than you need.

- Select your HD with care, an HD with only ony plate and one r/w head will consum less.

- If you use Linux as OS, you might not use X Windows... in that case you can prescind of keyboard, mouse and monitor. A keyboard and a mouse 24/7 could eat a bit of power in one year ;)

I hope that this could hep you... and sorry if my english is not very good, I'm not a native english speaker :)

2004-12-08 18:06:10
why not just use a laptop?
Well to get laptop like power savings, you could just use a laptop. Price performance wise, the options I've seen based on laptop parts don't save you much over the real thing. Laptops do tend to have rather smaller storage capacities, but you can make up for that by just keeping your file server appliance around and mounting it.

Their site seems to not be respoding at the moment, but I remember a device called a Briq that Yellow Dog Linux used to sell. Here is a URL:
Its a full PowerPC computer in a 5.25" drive form factor. You can just slip it into your desktop computer and attach to a standard power supply. PowerPC chips tend to be relatively low power as well.

2004-12-09 08:07:24
Other Alternatives...

I bought a little Cappucino PC summer of last year... it's not wildly powerful, only a 900MHz Celeron w. 256 MB RAM, but it works great as an internal development box.

And it's < 100 W.

2004-12-11 13:25:45
I would suggest the mini-ITX formfactor. The chips support longhaul frequency scaling (for even lower power use) and the newer cores (C5P, C5J) have entropy, AES and other crypto functions with more throughput than a P4.

Use of a laptop harddrive in the machine further reduces power consumption, and the onboard graphics and audio is also pretty decent.

The C5P core only consumes 1.5 watts at 533Mhz, and 3 watts at 1Ghz. Hard to beat that with any other system.

2004-12-14 00:53:44
compact flash system drive
I don't have facts for power consumption by compact flash cards, but I imagine that they are pretty low. A 512 MB card ($75?), an inexpensive ide <-> compact flash adapter ($20), and enough RAM (??) put you in business to run off a ramdisk. Then you have your centralized network storage solution that would be your main power draw...but you need storage somewhere.
2006-01-08 05:30:58
Low-Power Computing
I just saw your 2006 New Year's resolution to continue to push the low-power computing envelope and when I found this post on your past work, I wanted to share with you a set-up we at Geekcorps devised for remote communities out past Timbuktu, Mali (yes, that Timbuktu).

Its full computer set-up, CPU, monitor, even RBGAN satellite hook-up that runs off a single solar panel and doesn't need to be fan cooled even in Mali's desert heat.

The Mini-ITX chipset manufacturer, VIA Technologies, was so impressed, they sent one of their technicians all the way to Mali to check out the set-up on-site.