It took me a while to figure out why my work computer was so slow on Wednesdays. With a six core system and lots of RAM, I pretty much got used to my computer always being fast. Then I started using Virtual Machines to do my development work, and it's been a challenge ever since.
One thing I noticed was that my computer ran a little slowly on Wednesdays. It took a while for it to dawn on me that with the host computer patching at the same time all the VMs are patching, Wednesdays are not going to be very fun. Sometimes when I remember, I'll shut some of them down before they patch and let them patch staggered at a time of my choosing.
Today, I forgot to make them patch staggered, so I'm just letting them all finish. Hah, maybe next Tuesday night I will remember!