7.2. Hardware Design Criteria With the functional requirements determined, the next step was to establish design criteria for the SFF PC hardware. Here are the relative priorities we assigned for our SFF PC. Your priorities may, of course, differ.
Our SFF PC configuration is a well-balanced system. Other than expandability and video performance, which are unimportant to us for this system, all of the other criteria are of similar priority. Here's the breakdown:
Price Price is moderately important for this system, but value is more so. We won't try to match the price of mass-market consumer-grade systems, but we won't spend money needlessly, either. If spending a bit more noticeably improves performance, reliability, or cooling, we won't begrudge the extra few dollars.
Reliability Reliability ties for top importance with size. We'll make compromises in cost, performance, noise level, or any other criterion to make this system as reliable as it is possible to make an SFF PC. The case volume of an SFF PC makes it difficult to achieve reliability comparable to a larger system using similar components, but we'll do everything possible to build the most reliable system we can within the inherent limits of the small case.
Size Size is matched in importance only by reliability. If it isn't small, the whole exercise is rather pointless. Still, we didn't award this category the absolute highest possible priority, because there are some compromises we simply won't make. Bare-bones "shoebox" PCs are available that have literally half the case volume of the SFF system we eventually decided to build, but those tiny systems simply give up too much in return for saving a few inches.
Noise level Noise level is moderately important for an SFF PC. Our goal is a system that is unobtrusive in both size and noise level. Accordingly, we'll choose the quietest available mainstream components that otherwise meet our requirements for performance, thermal characteristics, and reliability.
Expandability Expandability is unimportant for our SFF PC. We may at some point want to make minor system upgrades, such as adding a PCI Express video adapter, an expansion card or two, more memory, and perhaps a second hard drive. To the extent that we can provide for such future expansion without compromising higher-priority considerations, we'll do so. But we consider expandability dead last in priority.
Processor performance Processor performance is moderately important for our SFF PC. Our goal was performance indistinguishable from a similarly-priced desktop system, which meant we needed a dual-core processor with mainstream performance. Ventilation and cooling considerations limited our processor choices to one of the new-generation low-current processorsan Intel Core 2 Duo or a low-current AMD Athlon 64 X2 model.
Video performance 3D video performance is relatively unimportant for our SFF PC because we do not intend to use it for gaming. We want enough graphics horsepower to run the Windows Vista Aero Glass user interface effects smoothly, but no more. The most recent Intel, ATI, and nVIDIA integrated video chipsets are sufficient for our purposes, and produce much less heat than a high-performance video adapter. We recognize, though, that many people may decide to build an SFF gaming system, so we tested various video configurations, from integrated video to a midrange nVIDIA 7600 GT. Although it is possible to install a high-end video adapter in an SFF case, a fast video adapter generates too much heat for the SFF case and draws more current than the typical SFF power supply can provide. We concluded that the realistic top-end for a video adapter in an SFF case is a midrange model, ideally one that is passively cooled.
Disk capacity/performance Disk capacity and performance are moderately important for a SFF PC. This is an easy criterion to meet, because current Serial ATA hard drives are huge, fast, cheap, and reliable. Fortunately, the best models are also relatively quiet and produce little heat. |
