We have a FreeBSD 64bit running on a esxi 4.1, the hardware platform is a DELL R710 with 2 x 56xx (intel 6core cpu) and 48 GB ram.
The FreeBSD vm is very slow, when we compiles/builds something on it, it takes 5 minuts and it says "build time 18 seconds.".
There's no vmtools installed on the vm.
The same vm is installaed on another R710 running esxi 4.0 for dell and there's no problems with that one. Does anyone have any idea about what to look for?

the VMs on the second server (ESXi 4.1) is a clone of the VMs running on the first VMserver (ESXi 4.0 Dell edition).
It's not possible for me to move the VM back to the first server since the file contaning the vm is too big. We installed the new esxi with a datasore with 8mb blocks because 1mb blocks dident allow for the file size we needed. It looks like the www server on the new ESXi 4.1 works fine, but I havent really tested it.
There's not installed vmtools on any of the VMs (FreeBSD). The block size on the second VM (ESXi 4.1) datastorage is 8mb and 1mb on the first (ESXi 4.0)