Hello. (First, sorry about bad english...)
Im Testing the workstation 9 on a Windows 7 and 8 Host. (First I tried with Windows 7, and now same problem with Windows 8).
I did a Guest, with windows 2003 server, and it works like a monster... (4 cores, 16gb ram, 200gb virtual hdd). Super fast, everything works good... BUT...
That working super fast, its so good, but after some time (some times after 5 min, other times after 2 hours), the host and guest goes to Super Slow... every click on the host or guest I need to wait 40 ~ 120 seconds to that click work, and the system only back to works normal again if I shut down guest. When it occurs, the hdd led lights every 1 or 2 seconds. Im looking in the Task Manager, and processor only 5 or 10% in use, I have a lot of free memory.
With great difficulty and slowness, I do power off on the guest and everything back to normal, I can power up guest again and continues working normally until the problem occurs again.
When i tried with Windows 7, i tried to put off the Real time protection of Security Essentials, and same problem... on Windows 8, did the same with windows defender. By looking other posts and texts, some guys says the Intel Turbo bust dont works good with a lot of virtualization technologies, then i tried to put Turbo Bust off too, but didnt works.
Why i tried to put Real time protection off? Because some times, when Im in the Chrome Navigator on the Host, and do some download, the problem of slow start and i get freeze on chrome and the system goes to Super Slow. This occurs not at all downloads, but on 10 i got the problem with 2 or 3 downloads.
If i dont have some guest powered on, i never get the problem.