Last but not least, we had a quick look at how the system power draw changes when you install popular add-on cards such as a network card or RAID storage controller. Although most motherboards come with at least four Serial ATA ports and one network port, it's sometimes necessary to add more drives or to add networking capabilities, for example, to hook up your system to a DSL modem or to two different networks.

We selected an Intel Pro/1000 MT Gigabit Ethernet card, which was designed for the PCI-X bus; these cards also work properly in a 32-bit PCI bus, although they'll be bottlenecked at 133 MB/s. The second card was an Adaptec 1430SA SATA RAID controller for PCI Express. It is a fairly affordable add-on controller that supports single hard drives or RAID arrays. The Intel network card added 2 W to the system power requirements, while the RAID controller added an additional 5 W to the system power draw at the plug.

Test Setup