When moving from a 32-bit to a 64-bit server, will apps take more memory on 64-bit machines because of the increased dataspace?
When moving from a 32-bit to a 64-bit server, will apps take more memory on 64-bit machines because of the increased dataspace?
No, but because of the increased pointer size (which also moved fom 32 to 64 bit per pointer).
Dataspace has to be USED to be consumed and recompiling the app does not magically make it use more memory. Some apps do (caching), but this is because of their logic.
No - the applications will use up the same memory, however you may find if the application being used was optimised for 64bit then it may actually use less memory.
The answer is YES apps will use more memory on a 64 bit OS, but not because of the dataspace, but for other reasons.
Note that we're not talking about vast quatities of overhead, we're talking about 100MB range, but its important to think about that in a Virtual Desktop environment, especially when you think you will be deploying hundreds of VMs