In a reprise of research published last year, French analyst Andreas Pfeiffer oversaw testing of what he calls "User Interface Friction," the fluidity and/or reactivity of an operating system to commands. He likens UIF to the reaction -- fast or not -- when stepping on a car's accelerator.
"We realized that there are many things you don't easily capture when you do normal benchmarking, such as elements in the user interface that slow down the user," Pfeiffer explained.
Among the tests run last year -- when Pfeiffer matched up Windows XP against Mac OS X -- and this year, when he added Vista, were benchmarks that quantified menu latency, common desktop chores, and precise mouse positioning.
"Menu latency is the time it takes an operating system to display a menu," said Pfeiffer. "In Windows, it's not immediate. That's not a speed or performance issue, but a design choice."
The new UIF data put Windows Vista, and its Aero graphical interface, behind Windows XP, which had showed improvement over earlier Microsoft operating systems. Menu latency, Pfeiffer said, remains a major problem in Vista, which scored 20 percent slower than XP. "Windows XP was a major step forward from Windows 98, but Vista is back to where 98 was," Pfeiffer said.
Microsoft declined to comment on Pfeiffer's Vista user interface research.
In the common desktop task benchmark, which gauged how long it took users to open a folder, delete files, and so on, Vista running Aero was 14 percent slower than XP. The final benchmark of mouse precision, a test crucial to design professionals and photographers, but also of interest to general users who get frustrated trying to nail submenu commands at the first click, also put Vista on the bottom. Pfeiffer's Vista "mouse precision coefficient" was 30 percent higher than XP's. A higher coefficient means users found it harder to precisely place the mouse.
"These things are very measureable," Pfeiffer said. "In Vista, a folder fades in, as if it appears out of nothing. It looks great, but after 10 times you realize you're losing time waiting for that."
Switching to the Basic or Classic interfaces, used primarily by low-powered systems and corporations that want interface consistency, respectively, improves Vista scores, but at a sacrifice of one of the OS's most compelling features. Dropping down to Classic gives Vista a menu latency score similar to XP's, but on desktop operations, it still lags behind the older operating system.
In every benchmark, Windows scored significantly poorer than Mac OS X, which is far more "fluid" than Microsoft's OSes, according to Pfeiffer.
"But this isn't a Windows versus Mac thing," Pfeiffer said. "We wanted to see if Vista improved on some of the weak spots of previous releases. Usually, developers iron out user interface issues over time to increase [user] productivity."
Not this time, he said. "Vista is a step back."
By Gregg Keizer
Computerworld (US online)
