Can old PCs run Vista?

Posted at: Monday 14th May 2007 by David Fearon

How well can an aging PC handle Microsoft's shiny new operating system, and is it worth upgrading your old machine as far as it can go? David Fearon tinkers with an Athlon XP PC and a Socket 478 Pentium 4 PC to find out.

Finally, there's the question of RAM. Both our original machines had 512MB - the standard memory complement at the time they were built. The Athlon was fitted with PC2700, and the Pentium 4 with PC3200. You probably won't need reminding of Vista's penchant for stacks of RAM - a lack of it has a far bigger effect on performance for both everyday desktop use and consistent gaming frame rates. So we opted for a decent upgrade here, to 2GB of PC3200 apiece, the standard amount for a decent new PC.

Installing and using Vista

Before upgrading, we had to establish whether it was necessary. After all, both machines meet Microsoft's minimum specification for running Vista. The official Microsoft specs state that Vista Basic needs a 1GHz CPU, 512MB of RAM and 32MB of video memory. No problems there. The specs for Vista Home Premium and Ultimate are higher, requiring the same 1GHz processor, but 1GB of RAM and a graphics card with 128MB of memory, hardware-level Pixel Shader 2.0 support and 32-bit-per-pixel colour modes. These extra requirements are to provide some leeway for running the Aero Glass translucent theme. We installed Vista Ultimate on both machines prior to upgrading to find out how they fared.

Say what you like about Vista, but one asset it does boast is good basic hardware support. Popping the install DVD into both test machines and rebooting to run through the clean-install routine, we expected at least one of the machines to hang, or moan about incompatible this or that. However, the only problem we had was the hesitancy of the routine - it paused for several minutes during the initial load-up while it puzzled over the old hardware and loaded default drivers. After that, it was plain sailing all the way to the first boot into the Vista desktop.

One thing we didn't obtain by default, of course, was the Aero theme but, aside from that, you'd initially be hard-pressed to tell the difference in responsiveness between our old machines and a new system. You see the same slight pause when opening menus (often accompanied by the spinning hourglass) that drives us nuts, even on spanking new quad-core systems, but that's the fault of Vista rather than the hardware. However, as soon as you start doing anything other than lightweight surfing, the low memory complement hits performance much harder than it does under XP. Running more than one sizable application at the same time results in a hell of a lot of swap-file grinding that simply doesn't happen under XP.

The Intel machine

The Pentium 4 in our old Intel system had a Northwood core with 512KB of Level 2 cache and an 800MHz FSB. While Northwood predates dual-core by several years, it was the first desktop CPU to feature Hyper-Threading - creating a virtual second core with its unused resources. The motherboard was an Abit AI7 fitted with the venerable Intel 865PE chipset. At the time of its launch, it was the equivalent of today's P965, with the 875P chipset being the equivalent of today's 975X. As with today's chipsets, the performance difference between 865PE and 875P was marginal to say the least, despite Intel claiming that the PAT (performance acceleration technology) in the 875P - which performed a little clever bus-traffic re-ordering optimisation - was the best thing ever.