Sadly, I didn't have access to an original Pentium 4 system for this article. My engineering test bed was long ago scrapped for parts, and I doubt that many of these old i840 chip-set-based boxes are still in use outside of the third world. However, I could at least evaluate the software stack itself. Through the magic of virtualization, we can see that, even with only 128MB of RAM, a Windows 2000-based configuration had plenty of room to perform. During OfficeBench testing, the entire suite consumed only 9MB of RAM, while the overall OS footprint never exceeded 132MB of RAM, roughly half of the available memory. Clearly this was a lean, mean version of Windows/Office. It chewed through the test script a full 17 percent faster than its nearest competitor, Windows XP (SP1) and Office XP. View the overall test results. View more detailed test results at xpnet.com.

The Bronze Age: Windows XP/Office XP
The introduction of Windows XP in 2001 marked the first mainstream (not just for business users) version of Windows to incorporate the Windows NT kernel. In addition to better plug-and-play support and other improvements, XP sported a revamped user interface with true-color icons and lots of shiny, beveled effects. Not wanting to look out of style, and smelling another sell-up opportunity, the Office group rushed out Microsoft Office XP (aka Office 10), which was nothing more than a slightly tweaked version of Office 2000 with some UI updates.

Hardware had evolved a bit in the two years since the Windows 2000 launch. For starters, Intel had all but abandoned its ill-fated partnership with Rambus. New Intel designs featured the more widely supported DDR-SDRAM, while CPU frequencies were edging above 2GHz. Intel also upped the L2 cache size of the Pentium 4 core from 256KB to 512KB (the Northwood redesign) in an attempt to fill the chip's stall-prone 20-stage integer pipeline. Default RAM configurations were now routinely in the 256MB range, while disk drives sported ATA-100 interfaces.

Windows XP, especially in the pre-SP2 timeframe, wasn't all that more resource intensive than Windows 2000. It wasn't until later, as Microsoft piled on the security fixes and users started running anti-virus and anti-spyware tools by default, that XP began to put on significant weight. Also, the relatively modest nature of the changes from Office 2000 to Office XP translated into only a minimal increase in system requirements. For example, overall working set size for the entire Office XP suite during OfficeBench testing under VMware was only 10MB, just 1MB higher than Office 2000, while CPU utilization actually fell 1 percent across the three applications (Word, Excel, and PowerPoint). This did not, however, translate into equivalent performance. As I noted before, Office XP on Windows XP took 17 percent longer than Office 2000 on Windows 2000 to complete the same OfficeBench test script. View the overall test results. View more detailed test results at xpnet.com. 

I was fortunate enough to be able to dig up a representative system of that era: A 2GHz Pentium 4 system with 256MB of RAM and integrated Intel Extreme graphics. Running the combination of Windows XP (SP1) and Office XP on bare iron allowed me to evaluate additional metrics, including the overall stress level being placed on the CPU.