Pentium 4 or Athlon?

It's PC shoot-out time again, and computer builders and buyers have a choice between machines built around Intel Corp.'s 1.7-GHz Pentium 4 processor and Advanced Micro Devices Inc.'s 1.4-GHz Athlon Thunderbird.Head-to-head comparisons of PCs using either CPU show that 1.7-GHz Pentium 4 PCs are faster than Athlon machines for running graphics-intensive and multimedia applications, such as video editing or uploading videos to the Internet. But the same machines with 1.33-GHz and 1.4-GHz Athlon processors generally outperform Pentium 4 units when running more prosaic business and office tasks.Most of the Intel systems included as base models for this guide came with a 1.7-GHz Pentium 4 processor, though several came with 1.4- or 1.5-GHz chips. They also had an Intel 850 chip set, a 400-MHz front-side bus, at least 128M of 800-MHz Rambus RAM and a 40G or 60G hard drive. They came with a variety of motherboards and a capable video card such as an nVidia GeForce with 32M or 64M of RAM.Comparable AMD systems came with a 1.4-GHz or 1.33-GHz Athlon processor, a 266-MHz front-side bus and at least 128M of RAM. The hard drives and video cards were similar to those of the Intel systems.I didn't select a monitor with any of the PCs I configured, although one can easily be added for prices ranging from $200 to $600 above the cost of a base system, depending on its size and type'say, a 17- or 19-inch CRT or flat-panel display.For comparison, I opted for CD-ROM drives; you might want a CD-RW or DVD drive, which cost more. In some cases, 56-Kbps modems, keyboards, speakers, Ethernet cards and mice came with the base unit ().When I had a choice of operating systems and productivity software, I chose Microsoft Windows 2000 Professional or Small Business Edition and Microsoft Office 2000 Professional. I did not include additional storage or RAID options with any of the products I configured.I found that you can get a well-equipped Pentium 4 PC for between $1,500 and $2,000, and a similar Athlon system for about $200 less. I predict that many Pentium 4 and Athlon systems will break the $1,000 price barrier by the end of the year as both Intel and AMD move their fastest CPUs closer to the 2-GHz speed limit.If you have a hard time getting your mind around the fact that slow processors sometimes outperform fast ones, some simple math might help.The performance of any CPU is measured by its raw speed in MHz or GHz multiplied by the number of instructions per clock cycle it can handle. Although the Pentium 4 is engineered for a maximum clock speed of 1.7 GHz, it can't handle as many instructions per clock cycle as a 1.4-GHz or even a 1.33-GHz Athlon. This means that the nominally slower Athlon can perform many tasks as fast or even faster than the Pentium 4.Take claims of being the fastest or best with a grain of salt. The processors were designed with different markets in mind.Intel focused on the popularity of the Internet and the need for rapid media processing. The Pentium 4 was designed from the outset to perform tasks such as streaming audio and video, and data imaging. For all its speed, it won't handle office applications much better than a slower Athlon or, for that matter, a fairly fast Pentium III.AMD, on the other hand, is still trying to wrest market share from Intel. It designed the Athlon to meet mainline business requirements for faster and more powerful word processing, spreadsheet use and e-mail.Before you invest in systems with either processor, remember again that other factors'including bus speed, RAM type, hard-drive type, video card, OS and even the applications it runs'have as much to do with determining a PC's overall performance as the processor.If you're interested in a head-to-head comparison of the systems that interest you, check these out first. Pentium 4 systems come with a 400-MHz system bus that provides data transfer rates of up to 3.2 Gbps. Pentium III systems came with a much slower 133-MHz bus. New Athlon systems come with a 266-MHz front-side bus. Virtually all Pentium 4 PCs come with Rambus dynamic RAM (DRAM). With advertised throughput rates of up to 800-MHz, RDRAM is much faster than the conventional synchronous DRAM used in most low-end and midrange Pentium III systems, which run at either 100 MHz or 133 MHz.But RDRAM has drawbacks. It uses a narrower interface'16 bits compared with 64 bits'than SDRAM, so its data pipe isn't as fat. RDRAM's inline memory modules, known as RIMMs, are more sensitive to magnetic interference than the dual inline modules used by SDRAM, which is why Intel had to recall its original 820 series motherboards.Finally, it is much more expensive than either conventional SDRAM or the double-data rate SDRAM used in new Athlon systems.DDR-SDRAM effectively doubles the speed of conventional SDRAM and offers equal performance to RDRAM at much lower prices. Pentium 4 PC manufacturers have complained that Intel's use of the 850 chip set locked them into the use of RDRAM, which incurred additional expenses that had to be passed on to consumers. In response, Intel recently announced the 845 chip set, which will allow system manufacturers to use DDR-SDRAM instead of RDRAM.In either case, you'll have to read the fine print carefully. Hard-drive performance is a key factor in overall system performance. A large 40G or 60G hard drive is important for today's demanding applications, but it's best to select one that spins at a rate of at least 7,200 rpm. I selected fast 48X or 52X CD-ROM drives as minimal gear with the systems I configured. A 32X CD-RW drive, or a 16X or 48X DVD drive, would be a nice addition to the system. Driving a high-end PC with an underpowered video card is like driving a Porsche with a Volkswagen engine. Why bother? For any Pentium 4 or Athlon system I recommend a card with at least 32M of RAM. Graphics designers and mediaphiles should shoot for 64M. TV-Out is a nice option, but it's not necessary unless you're a PC gamer.My advice? All other things being equal, if you must run high-end multimedia and video applications, by all means spring for a Pentium 4 system. For more common applications, your users will probably be just as happy with an Athlon system that costs about $200 less.