Lab Tests: Vista's Fast If You Have the Hardware

Illustration by Joe Zeff.
Illustration: Joe Zeff
With Microsoft's Windows Vista finally released to manufacturers and on the verge of making its way to retail, we can at last get down to the business of examining precisely how well the new OS performs. In our first tests, we discovered that while Vista's hardware requirements may be steep, it should run just fine--even with the Aero bells and whistles active--on machines that meet Microsoft's Premium Ready specifications (1GB of RAM, and a DirectX 9-capable graphics board with at least 128MB of dedicated memory).

We installed the RTM (release to manufacturing) Vista Ultimate code on desktop and notebook systems of varying specs and ages, and then we ran a series of benchmarks to answer several key questions about Vista's impact on performance. Our main findings:

  • Vista is generally slower than XP, but it's better at multitasking on dual-core PCs.
  • Your PC should have 1GB of RAM at the bare minimum.
  • Aero won't slow you down if you use a discrete graphics processor and enough memory.
  • Apps run slower on the 64-bit version of Vista, but adding RAM closes the gap.

Our conclusions here aren't the last word on Vista performance, however: When we conducted our tests in November, graphics companies were still fine-tuning their drivers (for example, we decided to drop our Doom 3 gaming tests because ATI's drivers didn't yet support that game's OpenGL graphics API).

Another note: Since we used updated, Vista-compatible versions of our Photoshop and multitasking tests from the beta of WorldBench 6, the results are not comparable with those for XP systems tested under WorldBench 5.

For more Vista information, tips, and answers to frequently asked questions, subscribe to PC World's Windows Vista newsletter.

Speed vs. XP

Microsoft typically claims increased performance for each new Windows version--but nearly every one requires a somewhat faster system to perform as well as its predecessor did. Our first Vista tests, though, showed some mixed results, and one very encouraging development.

Overall, our test apps did seem to run slower with Vista. On less-expensive or older hardware, the difference was pronounced. Our two low-end systems--an inexpensive 1.8-GHz Sempron 3400+ desktop PC from Dell with integrated GeForce 6150 LE graphics that rely on main system memory, and an aging 3-GHz Pentium 4 desktop from ABS using an ATI Radeon 9600 ProE card--ran our Photoshop test in Vista 23 percent and 13 percent slower, respectively, than they did in XP. Our results in the multitasking test and in the game Far Cry showed drops of 5 to 17 percent. (See the chart.)

On newer systems, the story gets a little more complex. We ran the same tests on a 2.2-GHz Athlon 64 X24200+ PC from Polywell equipped with a GeForce 7600GS card, and on a Micro Express system with a 2.4-GHz Core 2 Duo E6600 and Radeon X1600 graphics. Scores in the Photoshop test declined by a more modest 7 to 8 percent, but frame rates in Far Cry dropped dramatically.

The Polywell system endured a 25 percent hit in its frame rate, plummeting from 114 frames per second at 1024 by 768 resolution without antialiasing under XP to 85 fps in Vista. The Micro Express PC suffered a 12 percent drop. Bumping up to 2GB of RAM did nothing to improve frame rates on either system. Since gaming tests depend heavily on graphics drivers, though, the results should improve as ATI and nVidia continue to tweak their drivers for Vista.

Dual-Core Difference

On the other hand, if you have invested in a multicore system and are contemplating an upgrade, our multitasking test results are encouraging.

In this test we employ Windows Media Encoder to compress a video file in the background while we browse Web pages in Firefox in the foreground. On both dual-core systems, the test ran faster--29 percent and 31 percent faster on the Polywell and Micro Express systems, respectively--under Vista, indicating (as Microsoft has said) that the new operating system may be more efficient than Windows XP is at running multiple threads of code.

Memory Matters

Frequently an OS upgrade comes with a hidden cost: To maintain an acceptable level of performance, you must upgrade your computer's memory. Microsoft calls for a minimum of 1GB of RAM on Vista Premium Ready PCs, and our tests indicate that that amount is a good starting point. The Aero interface can run on a PC with 512MB, but you have to switch it on; by default, if Vista finds less than 1GB, it installs with Aero switched off.

Just for kicks, we ran a few Vista-versus-XP comparison tests with 512MB of memory installed on our low-end test machines. Though the multitasking test didn't slow down much, the Photoshop times nearly doubled under Vista. The moral of the story: Don't run Vista with less than 1GB.

Moving up to 2GB produced significant gains only in our Photoshop test (see the "Vista RAM Boost" test report). On the low-end P4 system, the upgrade to 2GB garnered a 10 percent performance boost. The dual-core Polywell desktop showed a more modest gain of around 5 percent (PC World generally considers performance differences of less than 5 percent to be unnoticeable in general business applications); meanwhile, an HP laptop with a 2-GHz Core 2 Duo T7200 processor and GeForce Go 7600 graphics ran 21 percent faster with the additional RAM.

Our multitasking and Far Cry tests showed little to no benefit from the increased memory. However, we would still recommend upgrading to 2GB of RAM if your wallet can handle it, as the additional memory will give your system lots of room for future growth.

The 64-Bit Story

Our tests of Vista's 64-bit version indicate that while programs generally run slower on it than they do on the 32-bit version, adding more RAM can help wipe out the difference (see the "Apps Run Faster on 32-Bit Vista" test report). With 1GB installed RAM, the Polywell and Micro Express PCs ran our Photoshop test 12 percent and 25 percent slower, respectively, in 64-bit Vista. When we moved both systems up to 2GB, the difference disappeared completely.

The delta on the multitasking test was much smaller--between 4 and 7 percent, regardless of the PC's memory configuration--and our gaming test results showed almost no difference. We don't know how often hardware vendors will put their latest drivers through the full testing and signing process for 64-bit Vista, but these initial results suggest that, as long as your system packs plenty of memory, you won't be taking much of a hit by going 64-bit.

Aero Overhead

Let's be honest: Much of Vista's appeal is tied to the operating system's flashy new interface. But what good is a slick new look if it slows your system to a veritable crawl?

The Aero interface may look as though it requires loads of graphics processing power to function properly, and Microsoft's Vista Premium Ready requirements--which cover the graphics hardware that a system should contain to run Aero--include a confusing sentence about needing DirectX 9, Pixel Shader 2.0, and 128MB of video memory. The good news is that systems equipped with almost any current graphics board will have sufficient muscle to run applications equally quickly regardless of whether Aero is turned on or off. However, we don't recommend running Aero on a PC that depends on integrated graphics (see the chart).

We ran our benchmarks with the Aero interface turned on and off. With Aero off, we saw little or no change in the Photoshop and multitasking results on machines that carried discrete graphics systems. In fact, with the Aero graphics turned on, both dual-core desktops we tested ran our Photoshop test just a smidgen faster.

Adding a faster graphics board to either of those systems had no effect on desktop application performance. (The effect on gaming benchmarks was profound, as you would expect whenever you install a higher-end graphics board.)

If your PC uses integrated graphics, however, there's a real benefit to turning Aero off. The 1.66-GHz Core Duo T2300 Toshiba notebook we tested ran our Photoshop test 16 percent slower with Aero on. Our Sempron-based Dell desktop system slowed down 6 percent in our Photoshop test when its integrated GeForce 6150 LE graphics chip (which uses the system's main memory) had to cope with Aero.


Our first tests of another intriguing Vista feature were a bit of a disappointment. ReadyBoost, a new technology that promises to enhance system performance by caching data on compatible USB thumb drives, actually caused a small performance drop in our benchmarks.

But this result may reflect more on the specific tests we ran than on the technology; we're working with Microsoft to make certain we can design tests that properly capture situations where ReadyBoost is supposed to work its magic.

It's Still Early

As we continue to develop Vista-ready benchmarks and to test as many systems with Vista preinstalled as we can get our hands on, we'll update you with additional findings.

In the meantime, if you are contemplating an upgrade, our preliminary tests suggest that Vista will be a decent performer on any machine with dedicated graphics hardware.

Looking back at our value-PC charts, most systems from two years ago--$1000 models carrying Pentium 4 processors of around 3 GHz or Athlon XP CPUs of around 2 GHz--would do just fine as Vista machines after a simple RAM boost. And dual-core desktop PCs appear to be great candidates for Vista upgrades.

Elliott Kirschling and Tony Leung of the PC World Test Center performed testing for this story.

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