You want low power? We've been running a FitPC2i (2GB
RAM, 2 GBit ethernet ports) for a year now.
It consumes a whopping 7 watts at full load (I've measured it, it's about 5 watts when idle).
Primary uses: DNS, DHCP, Firewall, HTTP Proxy and Samba
My one major complaint is apache. If I use ssh -X and lxsession to use log into the Zentyal user interface, the response is reasonable. If I connect from a workstation via https, the response ranges from ok to pathetic. I definitely wouldn't recommend it as a web server, although, come to think of it, my apt-cacher page loads instantly, although I'm not certain that it uses apache or has it's own web server.
We have a 750Mb internet connection which we regularly max out with no problems from the FitPC2i.
From an end-user's point of view, it does the job nicely. From an admin's point of view, where I depend on the web interface, it's irritating but workable. If I'm in a hurry, I just use lxsession and put up with the re-configuration of my workstation desktop.
Output from lshw, for anyone interested:
fitpc2i
description: Computer
product: CM-iAM/SBC-FITPC2i
vendor: CompuLab
version: Not Applicable
serial: Not Applicable
width: 32 bits
capabilities: smbios-2.5 dmi-2.5 smp-1.4 smp
configuration: administrator_password=disabled boot=oem-specific cpus=1 frontpanel_password=unknown keyboard_password=unknown power-on_password=disabled
*-core
description: Motherboard
product: CM-iAM/SBC-FITPC2i
vendor: Intel Corporation
physical id: 0
version: 1.x
serial: Not Applicable
*-firmware
description: BIOS
vendor: Phoenix Technologies LTD
physical id: 0
version: NAPA0001.86C.0000.D.1009141059 (09/14/2010)
size: 97KiB
capacity: 960KiB
capabilities: isa pci pcmcia pnp apm upgrade shadowing escd cdboot acpi usb agp biosbootspecification
*-cpu
description: CPU
product: Intel(R) Atom(TM) CPU Z550 @ 2.00GHz
vendor: Intel Corp.
physical id: 4
bus info: cpu@0
version: 6.12.2
serial: 0001-06C2-0000-0000-0000-0000
slot: U3E1
size: 2GHz
capacity: 2666MHz
width: 32 bits
capabilities: boot fpu fpu_exception wp vme de tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx constant_tsc arch_perfmon pebs bts aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 xtpr pdcm movbe lahf_lm tpr_shadow vnmi flexpriority pse
configuration: id=1
*-cache:0
description: L1 cache
physical id: 5
slot: L1 Cache
size: 64KiB
capacity: 64KiB
capabilities: asynchronous internal write-back
*-cache:1
description: L2 cache
physical id: 6
slot: L2 Cache
size: 512KiB
capacity: 512KiB
capabilities: burst external write-back
*-logicalcpu:0
description: Logical CPU
physical id: 1.1
width: 32 bits
capabilities: logical
*-logicalcpu:1
description: Logical CPU
physical id: 1.2
width: 32 bits
capabilities: logical
*-memory
description: System Memory
physical id: 12
slot: System board or motherboard
size: 2GiB
*-bank
description: SODIMM DDR2 Synchronous
physical id: 0
slot: soldered
size: 2GiB
width: 32 bits
*-pci
description: Host bridge
product: System Controller Hub (SCH Poulsbo)
vendor: Intel Corporation
physical id: 100
bus info: pci@0000:00:00.0
version: 07
width: 32 bits
clock: 33MHz
*-display UNCLAIMED
description: VGA compatible controller
product: System Controller Hub (SCH Poulsbo) Graphics Controller
vendor: Intel Corporation
physical id: 2
bus info: pci@0000:00:02.0
version: 07
width: 32 bits
clock: 33MHz
capabilities: pm msi bus_master cap_list
configuration: latency=0
resources: memory:d8080000-d80fffff ioport:1800(size=8) memory:d0000000-d7ffffff memory:d8000000-d801ffff
*-pci:0
description: PCI bridge
product: System Controller Hub (SCH Poulsbo) PCI Express Port 1
vendor: Intel Corporation
physical id: 1c
bus info: pci@0000:00:1c.0
version: 07
width: 32 bits
clock: 33MHz
capabilities: pci pciexpress pm bus_master cap_list
configuration: driver=pcieport
resources: irq:17 ioport:2000(size=4096) memory:d8100000-d81fffff memory:d8500000-d85fffff(prefetchable)
*-network
description: Ethernet interface
product: RTL8111/8168B PCI Express Gigabit Ethernet controller
vendor: Realtek Semiconductor Co., Ltd.
physical id: 0
bus info: pci@0000:02:00.0
logical name: eth0
version: 02
serial: 00:01:c0:08:8e:69
size: 1GB/s
capacity: 1GB/s
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress msix vpd bus_master cap_list rom ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=full ip=192.168.57.200 latency=0 link=yes multicast=yes port=MII speed=1GB/s
resources: irq:24 ioport:2000(size=256) memory:d8100000-d8100fff memory:d8500000-d850ffff(prefetchable) memory:d8520000-d853ffff(prefetchable)
*-pci:1
description: PCI bridge
product: System Controller Hub (SCH Poulsbo) PCI Express Port 2
vendor: Intel Corporation
physical id: 1c.1
bus info: pci@0000:00:1c.1
version: 07
width: 32 bits
clock: 33MHz
capabilities: pci pciexpress pm bus_master cap_list
configuration: driver=pcieport
resources: irq:16 ioport:3000(size=4096) memory:d8200000-d82fffff memory:d8600000-d86fffff(prefetchable)
*-network
description: Ethernet interface
product: RTL8111/8168B PCI Express Gigabit Ethernet controller
vendor: Realtek Semiconductor Co., Ltd.
physical id: 0
bus info: pci@0000:03:00.0
logical name: eth1
version: 02
serial: 00:01:c0:08:8e:6a
size: 10MB/s
capacity: 1GB/s
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress msix vpd bus_master cap_list rom ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half latency=0 link=yes multicast=yes port=MII speed=10MB/s
resources: irq:25 ioport:3000(size=256) memory:d8200000-d8200fff memory:d8600000-d860ffff(prefetchable) memory:d8620000-d863ffff(prefetchable)
*-usb:0
description: USB Controller
product: System Controller Hub (SCH Poulsbo) USB UHCI #1
vendor: Intel Corporation
physical id: 1d
bus info: pci@0000:00:1d.0
version: 07
width: 32 bits
clock: 33MHz
capabilities: bus_master
configuration: driver=uhci_hcd latency=0
resources: irq:23 ioport:1820(size=32)
*-usb:1
description: USB Controller
product: System Controller Hub (SCH Poulsbo) USB UHCI #2
vendor: Intel Corporation
physical id: 1d.1
bus info: pci@0000:00:1d.1
version: 07
width: 32 bits
clock: 33MHz
capabilities: bus_master
configuration: driver=uhci_hcd latency=0
resources: irq:19 ioport:1840(size=32)
*-usb:2
description: USB Controller
product: System Controller Hub (SCH Poulsbo) USB UHCI #3
vendor: Intel Corporation
physical id: 1d.2
bus info: pci@0000:00:1d.2
version: 07
width: 32 bits
clock: 33MHz
capabilities: bus_master
configuration: driver=uhci_hcd latency=0
resources: irq:18 ioport:1860(size=32)
*-usb:3
description: USB Controller
product: System Controller Hub (SCH Poulsbo) USB EHCI #1
vendor: Intel Corporation
physical id: 1d.7
bus info: pci@0000:00:1d.7
version: 07
width: 32 bits
clock: 33MHz
capabilities: pm debug bus_master cap_list
configuration: driver=ehci_hcd latency=0
resources: irq:21 memory:d8020000-d80203ff
*-isa
description: ISA bridge
product: System Controller Hub (SCH Poulsbo) LPC Bridge
vendor: Intel Corporation
physical id: 1f
bus info: pci@0000:00:1f.0
version: 07
width: 32 bits
clock: 33MHz
capabilities: isa
configuration: driver=isch_smbus latency=0
resources: irq:0
*-ide
description: IDE interface
product: System Controller Hub (SCH Poulsbo) IDE Controller
vendor: Intel Corporation
physical id: 1f.1
bus info: pci@0000:00:1f.1
logical name: scsi0
version: 07
width: 32 bits
clock: 33MHz
capabilities: ide bus_master emulated
configuration: driver=pata_sch latency=0
resources: irq:0 ioport:1f0(size=8) ioport:3f6 ioport:170(size=8) ioport:376 ioport:1810(size=16)
*-disk
description: ATA Disk
product: WDC WD7500BPVT-2
vendor: Western Digital
physical id: 0.0.0
bus info: scsi@0:0.0.0
logical name: /dev/sda
version: 01.0
serial: WD-WXG1EB0NHX11
size: 698GiB (750GB)
capabilities: partitioned partitioned:dos
configuration: ansiversion=5 signature=00078607
*-volume:0
description: Linux filesystem partition
vendor: Linux
physical id: 1
bus info: scsi@0:0.0.0,1
logical name: /dev/sda1
logical name: /boot
version: 1.0
serial: 2a106660-5d91-4484-a969-391933d05e96
size: 243MiB
capacity: 243MiB
capabilities: primary bootable ext2 initialized
configuration: filesystem=ext2 modified=2011-12-11 00:59:49 mount.fstype=ext2 mount.options=rw,relatime,errors=continue mounted=2011-11-26 00:46:02 state=mounted
*-volume:1
description: Extended partition
physical id: 2
bus info: scsi@0:0.0.0,2
logical name: /dev/sda2
size: 698GiB
capacity: 698GiB
capabilities: primary extended partitioned partitioned:extended
*-logicalvolume
description: Linux LVM Physical Volume partition
physical id: 5
logical name: /dev/sda5
serial: fwqJpw-giIV-KUbZ-adUa-N5KM-PTKS-rFdltZ
size: 698GiB
capacity: 698GiB
capabilities: multi lvm2
*-remoteaccess UNCLAIMED
vendor: Intel
physical id: 1
capabilities: inbound
*-network
description: Wireless interface
physical id: 2
logical name: wlan0
serial: 00:0d:f0:8d:e9:2f
capabilities: ethernet physical wireless
configuration: broadcast=yes multicast=yes wireless=IEEE 802.11bgn