I'm currently copying six large files across a 100MBit/s network from my Windows XP system to a Windows 2003 server. My PC is rather unresponsive and when I look at perfmon, I see that PhysicalDisk and Processor is bouncing around 20% but memory (pages/sec) is at solid maximum.
What is causing this? I thought the memory monitor was a generally indicating how much virtual memory page was being used.