I ran into a problem with very large image files. 700MB-3GB. When I click on them, my memory usage spikes. If the file is hosted on a network drive, the network usage jumps to 25% of a gigabit LAN connection.
This is just clicking on the file. It continues until the loading bar at the top of the explorer windows is done loading. If you click multiple files, the system will slow to a crawl and network usage will jump to 50%.
This is an i7 with 8GB of RAM running Win7 64bit. And it becomes un-usable until that loading bar is finished. I have tested it on a lower end system running Win7 32bit, I get the same results, only my whole computer locks up until its done.
Again, this is just clicking on the image files. I have it in detail view. I have also gone through the steps of disabling all thumbnails & thumbnail caching. And I have turned off all of the Aero interface to remove any sort of preview that WIn7 may be generating.
I again tested this on my home system and it did the same. And when I asked the question on Google+ I had someone else offer to help, they reported back the exact same results. They also tested in a Win8 preview they had and found that Win8 also does this.
Someone did some testing and found that it also does this to very large MPEGs as well.