One of the major distinctions between Windows XP (as well as its predecessors) and Mac OS was the fact that a Windows systems needed to be restarted daily to clear out system memory and improve performance, where I could run a Mac for days or weeks without seeing significant signs of system rot, the loss of memory performance due to poor memory management. At Microsoft, it is referred to as "WinRot." In Vista, it seems to me based on my testing, WinRot has become a thing of the past.
Following on yesterday's look at RAM use after startup, let's look at what happens when additional applications are opened on each system. To begin with, I opened Skype, which in my case has more than 100 contacts, so that it requires a lot of network calls to start, on both systems and found that Windows grabbed a much larger chunk of memory for the application compared to Mac OS.
After startup, Vista used 797.2MB of RAM, compared to 900.8MB when Skype was added to the mix, a gulp of 103.6MB RAM. Mac OS' RAM use increased by 57MB. Yes, Mac is still ahead, but that is what Mac users have come to expect. The issue underlying WinRot, though, is how the OS juggled RAM resources as applications opened and closed.
Vista's improved memory management appeared as another application, Firefox, was opened. Vista added about half a Megabyte of RAM, increasing its used memory to 901.6MB. Mac OS surrendered nine MB of RAM when Firefox opened. Here, you can see Mac's memory management showing its established strength as RAM is reallocated as one application gives up the resources it was using and another takes it up.
Vista's new SuperFetch memory management technology is also demonstrating its strength. Superfetch prioritizes data in RAM by recency of use, but also analyzes user habits by time of day, day of week and activities, so it does a better job of cleaning house than XP or its predecessors.
For example, if you open Skype all week long but never open it on Saturday, because on weekends you don't want to be disturbed by business calls, Superfetch will not keep Skype resources in memory as it would during the week. It also optimizes reloading of applications and makes better use of RAM. When Firefox was closed and launched a second time, for example, Vista reduced its RAM usage by 25MB because some of the resources previously allocated to Skype are dropped.
The additional analysis of user behavior seems to have eliminated Windows' habit of retaining DLLs and other Registry-dependent resources in RAM long after the application that first loaded it is closed or, even, uninstalled.
Now, when we start adding multiple applications, Vista starts to shine relative to the performance of Windows XP. It's keeping up with Mac OS for the first time. With Skype and Firefox running, the Mac adds 31MB RAM overall while Vista reduces its RAM usage by a half Megabyte.
With four applications running—another browser (in Vista's case, Internet Explorer, and Mac OS running Safari) and the mail applications that ship with each OS—the two systems consume similar amounts of RAM. Of course, this is dependent on the memory requirements for different applications, but the functionality is sufficiently similar to compare what you get for the RAM expended.
With the four applications open, Mac OS has increased its RAM usage by 51MB, to 860MB. Vista's RAM use has increased 20MB to 921.1MB. The difference is still only seven percent in RAM dedicated to system and application processes. Vista's use of memory doesn't increase relative to Mac OS as more applications load.
I examined the processes open on each OS, which reveals that Windows still comes in a lot more individual pieces, as Vista was running 3 times as many processes as the Mac OS with the four applications running. This reflects the more diverse hardware environment on which Vista runs, it is not a weakness given the improved performance in memory management.
During eight hours of work on the two OSes, opening and closing various applications and returning to the four opened for this experiment—Skype, Firefox, IE/Safari and Mail—both systems maintained their efficient use of RAM. Vista's RAM consumption after a full day was 57 percent of available memory and Mac OS was using 58 percent of its RAM.
With that kind of memory performance and based on my use of the system for the last couple weeks, it certainly seems that it is no longer necessary to reboot Windows every day.
It appears, then, that Vista and Mac OS are batting for the same average with regard memory management, something unprecedented since the transition to Mac OS X. There is not a winner, per se, because the two systems have reached a kind of parity for the time being. Mac OS X Leopard may take a step ahead of Vista, but today's verdict is that Windows Vista is much improved and performs memory-related tasks with equal efficiency.
Tomorrow, I'll look at Vista's ReadyBoost technology, which is a big benefit at the low-end of the market, where it can substantially improve the performance of systems with little RAM.
This is part of my continuing series comparing Vista and Mac OS X. Here are the earlier installments:
- Return to battle; no memory hogs found
- Waylaid by the blue screen of death
- Wide Area Wait
- Two flavors of Bluetooth
- Vista wireless and networking is catching up with Mac
- Minimum requirements; Vista isn't bloatware
- Hardware is where customization begins and ends
- Unboxing the ThinkPad X60 and MacBook Pro
- Before the starting gun (an explanation of the series)