For general use how much RAM do you really need for Windows XP? I would most often read that you need at least 512Mb RAM. I have to say that my experience tells me otherwise. A few years ago I bought a Pentium III (600MHz) PC which came with Windows 98 and ran fine with 64MB RAM. However as we all know Windows 98 is crap so I eventually upgraded to Windows 2000. With 64MB of RAM the PC was much slower with Windows 2000 than with 98. I upgraded to 128MB and the speed was restored. A while later Windows XP came out and while I was happy with my Computers performance and stability with Windows 2000, I was eager to try this new look version of Windows (after all Windows 2000 basically looked just like Windows 95). Once upgraded the PC was once again dead slow. Managed to get my hands on a 128MB memory module and replaced one of the 64MB modules (PC only had 2 slots). With the 192MB Ram the PC was much much more useable than it had been with 128 but was still not restored to the speed it had been with Windows 2000 and 128MB. Then I purchased a new home PC (the above was my business machine) which came with 256MB. This PC was a speed demon compared with the work PC (but I put this down to the Celeron 2.2GHz compared with a Pentium III 600Mhz CPU not the memory size). However a second compatible 128MB memory module came into my hands allowing me to replace the remaining 64MB module bringing the Pentium IIIs memory to 256MB. This restored its performance to what it had been with 128MB under Windows 2000. I have since upgraded my home PC to 512MB and seen no percievable increase in performance (compared with having 256 fitted). I have also replaced the Pentium III system with an Athlon64 machine initially fitted with 2GB. 1 GB of that failed so currently the machine has 1GB while I wait for the replacement. I have to say I see no reduction in performance with this loss of RAM. All this leads me to believe that anything less than 256Mb impairs Windows XP performance but that anything over 256MB has very little advantage for the speed of general OS tasks (ie opening windows etc), MS Office 2003 operation, Adobe Photoshop or using Nero Vison Express to transcode captured DV.
You are correct, just to be running the OS you don't need that, but the more programs you start running concurrently the more RAM is required. It also depends on the program. For instance, I noticed a huge performance increase in World of Warcraft going from 512m to 1 gig of memory. While I was in the game if I wanted to look up something on the web, it would have to page to hard drive every time I alt+tabbed to get back to my browser. Once I put a gig of memory in, it does not have to do that and I get to my browser instantly.
