I currently have a Window 2008 standard on ESX which host the MOSS 2007 with MOSS SP2.
The SQL server is SQL server 2008 on a Windows 2008 standard and it is a physical server.
I use a PC with windows xp to upload a big file of 67MB to a site collection->Documents->Shared Documents using the Upload -> Upload Document . after a few seconds the IE 8 redirected me to page not found error page and the whole Windows 2008 server slow down to crawlling. I did reboot the system a few time and it have the same slow performance.
When downloading an exist file from the Documents->Shared Documents, it speed slow to 20KB/s in the intranet. Just the day before i manage to download at a speed of 2MB/s.