This question is one of a pair of questions that are related, but different enough to split up. For reference, the other question is "How do I get my virtual machine to use both monitors [again]?"
I have a VM for every Windows operating system from XP to 8.1. When I was running Workstation 7, I was able to switch between machines in the blink of an eye. I upgraded to Workstation 10 to be able to install Windows 8.1. Now, switching between machines takes about 3 sec if the machines are spread across two monitors (about half that for a single monitor set-up).
For reference, my hardware includes a Gigabyte GA-X58-USB3 motherboard, an Intel i7-980X microprocessor, 24 GB RAM, and a Sapphire 100315L Radeon HD 6850 graphics card. Both Workstation 7 and Workstation 10 were installed on this hardware on the same instance of Windows 7.
So is there anything I can do to get back to "blink of an eye" switching with Workstation 10?