Motherboard (AMD): ASUS A7N8X-VM/400
For a budget system, we allocate 15 to 20 percent of the total budget to the motherboard, which is to say $75 to $100 for a $500 system. To stay within the overall budget, we needed a motherboard with embedded video, audio, and LAN functions. There are many Socket A motherboards available, but some of them support only Athlon XP processors. We considered only motherboards that explicitly list support for K7 Sempron processors, which narrowed the field.
Sempron motherboards that use various chipsets are available, but we strongly prefer motherboards based on nVIDIA nForce-series chipsets. For the K7-class Sempron 2400+, we think the nForce2 IGP chipset is the best choice. Of the nForce2 IGP motherboards available, we chose the ASUS A7N8X-VM/400 based on the reputation of ASUS for top-notch build quality and rock-solid reliability.
The microATX A7N8X-VM/400 motherboard includes integrated GeForce4 MX video, which provides decent 2-D display quality and 3-D acceleration sufficient for casual gaming. There is also a standard 8X AGP 3.0 expansion slot available for future video upgrades, and three PCI slots. The A7N8X-VM/400 supports a maximum of 2GB of DDR memory in two memory sockets, which we consider marginal but adequate for a budget system.
Integrated 6-channel PCI audio is provided by a C-Media 8738 audio chipset and a Realtek ALC650 codec, and Ethernet connectivity by an integrated nVIDIA 10/100 Ethernet controller. The A7N8X-VM/400 provides the usual complement of ports, including six USB 2.0 ports. About the only thing missing is Serial ATA, which we do not consider a significant drawback.
At $78, the ASUS A7N8X-VM/400 motherboard provides all the functionality we need at a reasonable price. The only other nForce2 IGP-based motherboard we'd consider using is the MSI K7N2GM2-LSR.
Motherboard (Intel): Intel D865GBFL
The full-ATX Intel D865GBF is our "default" Socket 478 motherboard, which is to say we use and recommend it unless there's good reason to use something else. The D865GBF exhibits Intel's typical top-notch build quality and is rock-solid reliable. We have never had any stability or compatibility issues or other problems attributable to the D865GBF.
The D865GBF includes integrated Intel Extreme Graphics 2 video, which provides excellent 2-D display quality. Despite the name, Extreme Graphics 2 provides pedestrian 3-D graphics performance at best, although it can handle nondemanding games. The D865GBF provides a 1X/4X/8X Universal AGP 3.0 expansion slot for future video upgrades, and six PCI slots. It supports a maximum of 4GB of DDR memory in four memory sockets, which allows plenty of room for future memory upgrades.
The integrated SoundMAX 4 XL with AudioESP audio subsystem provides 6-channel audio using the Analog Devices AD1985 codec. The D865GBF is available in three variants that differ only in LAN support. The D865GBF has no LAN adapter; the D865GBFL has an integrated Intel 82562EZ 10/100BaseT LAN adapter; and the D865GBFLK has an integrated Intel 82547EI 10/100/1000BaseT LAN adapter. All three models provide the usual complement of ports, including eight USB 2.0 ports, two standard ATA interfaces, and two Serial ATA interfaces. (We elected to use standard ATA drives for our budget Intel system because S-ATA drives sell at a small premium, but having S-ATA interfaces is a plus for future upgrades.)
At $99, the Intel D865GBFL motherboard is at the top of our price range, but it provides all the features and functions we want. You can save $5 or so by using one of our alternative selections, the Intel D865GLCL or the ASUS P4P800-VM, without giving up much other than a few PCI slots. Both are microATX boards based on the Intel 865G chipset.
Memory: Crucial PC3200 DDR-SDRAM
We thought carefully about how much memory to install in these budget systems. Some cheap mass-market systems provide only 128MB of memory, which we consider insufficient, particularly for Windows XP. We think 256MB of memory is reasonable for a budget Windows XP or Linux desktop system, so that's what we decided to install.
Cheap memory is one of the two leading causes of PC problems, the other being cheap power supplies. We use only first-rate memory even for budget systems, and we strongly suggest you do the same. Using generic memory, we could save a few dollars, but at the expense of frequent crashes and potential data corruption. We'll stick with good memory, and it doesn't get any better than Crucial.
We used the Crucial Memory Configurator to list the memory modules that are compatible with each of our motherboards. We chose one $43 Crucial PC3200 256MB CT3264Z40B DIMM for the AMD system and one $43 Crucial PC3200 256MB CT3264Z40BB DIMM for the Intel system. We could have chosen two $27 Crucial PC3200 128MB CT1664Z40B DIMMs for the AMD system and two $27 Crucial PC3200 128MB CT1664Z40BB DIMMs for the Intel system. That would have increased our memory cost by $11 for each system, but there were reasons we considered doing so.
If you've delved into the technical specs for the AMD processor and ASUS motherboard, you might wonder why we chose PC3200 memory rather than PC2700 memory. The AMD Sempron uses a 333MHz memory bus, which requires only PC2700 memory, but we chose PC3200 modules for improved flexibility in the event we later decide to swap those modules into a different system. A system that requires PC2700 memory can use PC3200 memory; one that requires PC3200 memory cannot use PC2700 memory. In theory, using memory that's "too fast" can actually degrade memory performance. In practice, we've never seen that effect, and most motherboards allow you to configure memory speed in BIOS setup.
The ASUS A7N8X-VM/400 motherboard has only two memory slots. If we installed two DIMMs, there would be no room for expanding memory later without removing one or both of the modules we'd already paid for. By installing one DIMM, we left one memory slot open for future expansion. It's true that using only one DIMM forces the memory controller to operate in single-channel mode, but the additional bandwidth of dual-channel memory is wasted on the Socket A Sempron. With a 166MHz bus (dual-pumped to an effective 333MHz), the memory bandwidth of the Sempron is 2,667MB/sec, the same as that of single-channel PC2700 memory. So, for the AMD motherboard, installing one 256MB DIMM is not only cheaper than installing two 128MB DIMMs, but it also leaves our options open for future memory upgrades.
Choosing memory for the Intel D865GBF motherboard introduces other issues. The D865GBF has four memory slots, so populating two of them still leaves room for expanding the memory later. Like the ASUS A7N8X-VM/400, the Intel D865GBF can operate memory in single- or dual-channel mode. But the Celeron D uses a 133MHz quad-pumped bus, for effective memory bandwidth of 4,267MB/sec. That's well above the bandwidth of single-channel PC3200 memory, so if we use single-channel memory the processor will sometimes sit idle waiting for data from memory. so enabling dual-channel memory improves performance.
But enabling dual-channel memory operation requires installing DIMMs in pairs, so the question becomes whether improved memory performance is worth the additional $11 cost of two 128 MB DIMMs versus one 256MB DIMM. That's a difficult question to answer, because the performance benefit of dual-channel memory depends on the application being run. Considering the mix of applications likely to be run on a budget system, we decided to save the $11 for use elsewhere and install a single 256MB DIMM.
While 256MB of RAM is sufficient for Windows XP or Linux running typical productivity applications, it is marginal for memory-intensive applications such as multimedia, image editing, and so on. If you will use the system for such applications, consider spending the additional $40 or so that it costs to upgrade memory to 512MB. To upgrade the AMD system to 512MB, use one Crucial PC3200 512MB CT6464Z40B DIMM. To upgrade the Intel system to 512 MB, use two Crucial PC3200 256MB CT3264Z40BB DIMMs. (Two 256MB DIMMs cost only $5 more than one 512MB DIMM, which we consider worth spending in a 512MB system for the additional memory performance.)
Hard drive: Seagate ST340014A 40GB Barracuda 7200.7
Many cheap mass-market systems use 5,400-rpm ATA drives, which we consider a foolish way to save a few bucks. A 5,400-rpm hard drive has no place in a modern system, even a budget model. The difference between a 5,400-rpm drive and a 7,200-rpm drive is clearly perceptible to most people. With the 5,400-rpm drive, everything seems slower--the system takes longer to boot, programs load at a leisurely pace, even web pages seem to take longer to load. So we decided that even on a tight budget, it made sense to go with a 7,200-rpm model.
The brand wasn't in question. We've used and recommended Seagate hard drives for years. Seagate Barracuda-series drives are inexpensive, fast, quiet, cool-running, extremely reliable, and come with a five-year warranty. The only decision was which model. Seagate makes Barracuda drives in various capacities in standard ATA and Serial ATA interfaces. Some models have a 2MB cache and others an 8MB cache. In general, Serial ATA models, all of which have an 8MB cache, are slightly faster and slightly more expensive than standard ATA models. Some models are available in retail packaging and others in OEM (bare drive) packaging. To minimize cost, we decided to look at only OEM models.
For a budget system, we normally allocate 10 to 15 percent of the available funds to the hard drive, or about $50 to $75. If disk capacity is a high priority, we may go as high as $100. The table below shows the Seagate Barracuda OEM drives available in that price range.
Seagate hard drives under $100
Keeping our budget in mind, we chose the 40GB model for our system. But this system will be a node on our network, which has terabytes of shared disk space available. If this were a stand-alone system, we might install a larger hard drive. An extra $9 buys us 40GB of additional disk space and still keeps us within our original $50 to $75 budget.
S-ATA models sell for about a $10 premium, which we can't justify for a budget system. Increasing the cache from 2MB to 8MB costs only $4 for the 120GB models but $8 for the 160GB models. The larger cache improves performance marginally. We probably wouldn't pay $8 extra for the 8MB 160GB model, but we might consider springing for $4 to upgrade the 120GB model to an 8MB cache. On the other hand, that extra $4 might be better spent upgrading to a 160GB model with only 2MB of cache, depending on your priorities.
Keep in mind that the prices we use here are snapshots taken at one moment in time. When you purchase a drive for your own system, check prices on the various models and make your decision based on your own priorities. Also remember that hard drives are on sale frequently and various rebate offers are available. With careful shopping, you may be able to find much more hard drive for your money.