In all of the commotion over the introduction of Vista and since, one thing is obvious: Vista needs speed more than Mars needs women. Early reports from Vista users can make it sound like they're dealing with two different products: a Good Vista and a Bad Vista. Some users talk about how fast it is, how quickly it boots up, while other complain about how slow it feels.

The key seems to be that Vista's performance is extremely hardware-dependent. Running Vista on a 2GHz processor, 2GB of RAM and a 256MB video card can be a very pleasant experience. But Trying to run Vista on a marginal hardware set-up can be an exercise in frustration. Getting good performance out of Microsoft's Windows Vista requires more of everything -- more system memory, a faster CPU, more hard-disk space, and much more graphics processing power.

Of all these, system memory is the most important, because it impacts the performance of the others. For example, the graphics subsystem might borrow system memory, which in turn diminishes memory available for caching data and program code pages, which could force the processor to wait . . . and wait . . . for data to be read off the hard drive.

Vista does what it can to optimize this digital choreography. Caching technology, in particular, has been pushed beyond anything available in previous versions of Windows. A new memory-management technology called SuperFetch works like a combination of fortune teller and inventory clerk to predict the data the CPU will ask for next, and make sure it's on the system memory shelves, where it can be delivered to the CPU fastest.

"Ready" For Vista
But software optimization can only do so much, and Vista also includes technology to support some relatively new hardware solutions for improving its performance. The names of some of these functionalities were in flux during Vista's long development process, but with the OS finally shipping, the list has settled on a common family name: "Ready." It has three main members:

• ReadyBoost uses flash memory in external devices -- USB drives and memory cards, for example -- to supplement system memory with a special cache that takes advantage of flash devices' very quick random read times to boost system performance.

• ReadyDrive takes advantage of new hybrid hard disk drives (abbreviated H-HHD) that combine conventional rotating disk storage with flash memory. Vista treats the flash and disk as one memory space, so that it can be used for caching frequently-needed data, for ReadyBoot data, or as a disk-write cache when the disk is spun down, in order to save battery power.

• ReadyBoot uses the ReadyBoost services to tackle one particular problem -- speeding up the processes of booting the system and recovering from hibernation. It keeps track of the files most often needed when the system boots and builds a temporary cache -- sort of a "Boot-Up's Greatest Hits" -- when the system starts. It can use flash wherever it finds it in either external flash devices or H-HHDs.

ReadyBoost and ReadyDrive are matched to new kinds of hardware products. In addition to H-HHDs, flash drives marked "Enhanced for ReadyBoost" are making their way to the market, fast flash memory cards popular for digital cameras are finding new uses, and embedded flash memory is even appearing on special "Enhanced for Vista" motherboards.