Now that notebooks outsell desktop PCs and low-power and low-priced netbooks are so popular, mobile performance and battery life will matter more than ever for Windows 7. “The notebook used to be just a mobile desktop,” points out Microsoft’s vice president for Windows Product Management, Mike Nash. Now, he says, notebooks need to cope with more complicated scenarios. “A machine will turn on in one place, turn off in another, go to sleep on one network, wake on another,” Nash says. Windows 7 is intended to give notebooks longer battery life, easier networking, better security, and run on much less-powerful machines than Vista—including netbooks.
At the recent Windows Hardware Engineering Conference (WinHEC), Microsoft showed Windows 7 running on a range of netbooks, including the Asus EEE 901 PC, the Dell Inspiron Mini 9, the MSI Wind and even the VIA-powered HP 2133 Mini-Note. Microsoft didn’t set out to create a special version of Windows 7 for low-power machines like netbooks, but general improvements in performance turn out to make a big difference—especially changes to the Desktop Windows Manager. In Vista, the amount of memory used increases linearly as you open more windows; in Windows 7, as long as you have a WDDM v1.1 driver, opening more windows uses much less additional memory.
Using a beta of Windows 7, we were able to open over 100 windows in a mix of applications on a Lenovo X300 notebook with Intel 965-based graphics and a WDDM v1.1 driver, without seeing a warning about the system running slow enough to suggest switching to Aero Basic. On a Dell Inspiron Mini 9 with an Intel Atom processor, which has Intel 945-based graphics for which we couldn’t find a WDDM v1.1 driver, we saw the warning with only 21 windows open; performance, however, was as good as with Windows XP, if not better.
Other performance improvements reduce the amount of disk I/O for reading from the registry and indexing files for search, and improve low-level kernel operations that could slow down access to the Start menu and Taskbar. Windows 7 also loads fewer services when you boot. This doesn’t just get you started more quickly; it means there are fewer services actively resident in memory just because you might need them. When you do something that requires a service, Windows 7 loads the service on demand and then unloads it once it’s no longer required—thus freeing up memory.