What is the difference between hyper-V and virtual_pc?

There are many differences. The comparison between Virtual PC and vitual server and virtual server and hyper-V is more comparable.

1. vitrual PC can only Virtualize a 32-bit system. Even if a 64-bit vitual PC runs, it can only Virtualize a 32-bit system, microsoft will no longer launch a virtual PC version capable of virtualizing a 64-bit System
2 Virtual PC hardware is virtual, and hyper-V runs directly on the physical server hardware on the hypervisor layer. All virtual partitions communicate through the hypervisor hardware, and the hypervisor is very small and efficient.CodeTo coordinate these calls.
3 Virtual PC can be installed on any machine, and hyper-V is not,
1. The CPU on the physical machine is required to support virtualization commands (Intel is called inter-VT, AMD is called AMD-V), which needs to be enabled in BIOS.
2. the CPU supports Data Execution Protection (DEP ).
3. Windows Server 2008 must be a 64-bit system.

in enterprise applications, if Microsoft products are selected before hyper-V, virtual server rather than virtual PC is selected.
1. hyper-V is integrated into Windows Server 2008 as a component. [No separate payment required]
2. The virtual machine performance is greatly improved by leveraging the virtualization functions provided by the underlying processor.
3. The management layer abstracted between hardware and virtual machines is thinner, providing better performance than Virtual Server 2005. [Hypervisor]
4. multi-processor support for virtual machines. hyper-V Supports up to four processors, and Virtual Server 2005 R2 supports only one.
5. A 64-bit operating system can be installed on a virtual machine, but the operating system hosted on the outer layer must also be 64-bit.
6. The IDE channel supports up to 2 TB of virtual hard disk storage. [Virtual Server 2005 supports a maximum of 127 GB]
7. unlike Virtual Server 2005's Web interface for host and Virtual Machine Management, hyper-V integrates the management interface into the system's MMC.
8. It is clear that Microsoft has plans to release hyper-V into an independent component. In the future, it can be directly installed on bare metal without the support of any operating system. Therefore, in the future, you will be able to directly install and use virtual Windows or Linux on windows without paying for the Windows operating system.
9. In hyper-V, the NIC of the VM is 10 Gb, and 2005 MB in virtual server.
10. You can specify multiple VLAN IDs for the virtual network.
11. snapshot! It can save the status of the Virtual Machine without suspending or disabling the Virtual Machine and create a copy of the Virtual Machine hard disk. The snapshot function can be used to save the entire virtual machine status [not only the Virtual Machine hard disk content, but also the virtual machine configuration information]. In hyper-V manager, you can track the snapshots of your tampering room and restore the status of your VM to any snapshot you have previously created.
12. Fedora 8 can run well in hyper-V beta.
13. hyper-V virtual machines support a maximum of 64 GB while Virtual Server 2005 supports only 3.6 GB.