So I have been hearing this a lot lately and wanted to get a link out to a good article which explains superfetch and what it is doing. I will have to admit the first time that I opened task manager in Vista and saw my system running at ~1.6GBs I thought I had a memory leak of some sort, but once I determined this not to be the case I was perplexed. Where is all the RAM in my system going? Is Vista really that bloated?
Well perception is everything (or a lot), so I wanted to point out this article which does a good job of summarizing Vista and the use of "superfetch".
It turns out that Vista is not bloatware, but in essence is caching items that it thinks I am going to use in memory, henceforth making effective use of the RAM I have in my system.
Windows XP or Linux usually also use whatever RAM is free to do disk read caching (speculatively too whenever there is free time/space, without inventing a new buzzword like "superfetch" for that), leaving just a few megabytes genuinely unused for fast allocation by software. So, you cannot really draw any conclusions from the amount of free RAM.
The author of the original article got a misconception, because XP task manager lists available RAM INCLUDING disk cache, while Vista lists cache and free RAM separately. Disk read cache is not technically "free", yet it qualifies as available, because memory just needs to be unmapped to be usable by software, which is an instant operation.
Things you can draw conclusions from though, are minimal system requierements and swapfile space used. With XP and todays's most Linux distubutions, one would see rapid decrease in swap use between 256 MB and 512 MB installed system RAM, which marks the point from which the operating system is quite comfortably usable. Now, tried running Vista with 512 MB system RAM? Even 1GB systems seem less than comfortable, or so i heard. If we look at the screenshots and add swapfile space used and unavailable (genuinely taken, non-disk-cache) RAM, we get around 700 MB for XP vs. whopping 2300 MB for Vista!
I'm definately not trying Vista on my 512MB computers.
Vista certainly appears to be a memory hog. But when dealing with complex technology appearances are often deceiving. Few computer users really understand virtual memory and virtual memory changes everything. The traditional ideas of saving RAM just don't apply anymore.
In a virtual memory system memory usage will usually be much higher than physical RAM, yes, even with 4GB. Program code and data will be stored in RAM, the pagefile, or in one of many other files. RAM is orders of magnitude faster than the others. In such a system you want RAM to be used to the fullest possible extent. Frequently used data will be in RAM while the rest on disk. This is a dynamic state that changes according to need. A large amount of free RAM indicates that the system has failed in it's duties. In spite of what Task Manager might seem to indicate, XP is very good at this. Vista is even better.