Originally Posted by
Ghostsix.Midgard
open task manager while ffxi is running and watch your processes. When the spike appears sort the column from largest to smallest and you might notice what's causing it.
could be a virus or an antivirus program running in the backround, maybe a limewire or sharing software uploading in the backround as well.
also WMP11 has a networking/sharing feature which can lag your system at times.
a few suggestions off the top of my head, also maybe the videocard/processor is overheating?