If you do not have a Mac Pro, quad core iMac or Xserve than only assign 1 virtual cpu to the vm. You can't assign physical cores to Fusion, Parallels or VirtualBox, the OS and the virtualisation will spread the load between the physical cores so it happens automatically. Windows 7 runs at it best with 2 GB of memory. Don't use any more because it will leave OS X with less memory which it's not going to like. You could run Win7 with 1 GB of memory if you want.
If you have 2 physical cores you can only assign 1 virtual cpu; if you have 4 physical cores you can only assign 1 or 2 virtual cpu's; if you have 8 physical cores you can only assign 1, 2 or 4 virtual cpu's; if you have 16 physical cores you can only assign 1, 2, 4 or 8 virtual cpu's. Assigning more virtual cpu's will end in a dead slow vm and a dead slow Mac. It will become an unusable situation so never ever assign the same amount of virtual cpu's as there are physical cores!
That's probably because Visual Studio requires a lot more memory than 1 GB. People using 1 or 2 GB of memory in their Visual Studio vm/machine seem to be reporting a lot of performance problems. Upping the ram resolves it.
Or use something that is suited for a lot of iops like the new OCZ Vertex 2; it uses the Sandforce controller with the "special" firmware that enables the ability to have 22,500 iops instead of the default 10,000. If you don't have an enormous amount of money for a ssd the alternative would be to put it on another (separate) disk. I don't think a Drobo would be a good idea, it has too much overhead already making it a lot slower than other external firewire drives.
do you have a HDD or SSD? your experience wont be as good with a HDD.That gives me hope. My XP VM experience is similar to yours. I upgraded my machine (2009 MBP w/ 4GB) about the same time I upgraded to 3.0, and saw an overall performance decrease.I've found that if I quit Safari before starting up the VM, things go much more smoothly. If I don't, it takes 5+ minutes to get to the point that it's responsive enough to use. Hopefully 3.1 resolves this. I'll have to give it a try when I get home.
I see on the VMWare site that there are benefits to XP that you only get if it's an XP VM created with 3.0 or later. Anybody know how you can tell which version was used to create the VM?
HT is enabled by default so OS X will see 4 cores. The problem is that HT only uses the parts of the cores that aren't in use. The question is what will Fusion or any other virtualisation app benefit from that and will you be able to assign 2 virtual cpu's successfully without bogging down the system. From what I read on the Fusion forums is that this is something they are wondering as well and they're looking into it. I doubt HT will be useful if you want to add multiple virtual cpu's due to the way it works.silly me then. i wonder if they will bring HT into it at all
Use the 64 bit of any OS if possible. Running 64 bit guest OS's will require VT-x support (which the i5 has) and this will speed things up. In the end a 64 bit guest OS performs better than a 32 bit OS in Fusion (even though the 32 bit binary translation is among the fastest).
