Difference between Windows Server 2008 & Windows Server 2012
Below are the basic difference  between windows Server 2008 and windows Server 2012
First we’ll discuss about the Hardware requirements and then we go through the Features

Hardware Specifications between these two

Processor/Memory FeatureWindows Server 2012Windows Server 2008 R2
RAM per VM1TB64GB
Virtual processors/VM644
# of Active VMs1,024384
Virtual processors/VMs644
Virtual processors/hosts2,048512
Maximum cluster nodes6416
Maximum cluster VMs8,0001,000
Physical Memory4TB1TB

Features which are supported in Windows Server 2012 and that are Not supported by windows server 2008 as shown below:

New Features
Private VLANSupportedNot Supported
DHCP GuardSupportedNot Supported
Router GuardSupportedNot Supported
Hyper-V Extensible SwitchSupportedNot Supported
Extension MonitoringSupportedNot Supported
IP Address rewriteSupportedNot Supported
Generic Routing EncapsulationSupportedNot Supported
Non-Uniform Memory Access (NUMA) support inside VMsSupportedNot Supported
Single Root I/O Virtualization (SR-IOV)SupportedNot Supported
Hyper-V Smart PagingSupportedNot Supported
Resource MeteringSupportedNot Supported
Runtime Memory ConfigurationSupportedNot Supported
Virtual Hard Disk formatSupportedNot Supported
Offload Data TransferSupportedNot Supported
Data Center BridgingSupportedNot Supported
Virtual Fibre Channel in Hyper-VSupportedNot Supported
QoS Minimum BandwidthSupportedNot Supported
Encrypted cluster volumesSupportedNot Supported
Cluster Shared Volume (CSV) 2.0SupportedNot Supported
Application MonitoringSupportedNot Supported
Storage SpacesSupportedNot Supported
Data DeduplicationSupportedNot Supported
SMB DirectSupportedNot Supported
Multi-terabyte volumesSupportedNot Supported
SMB Transparent failoverSupportedNot Supported
Datacenter Diskless bootSupportedNot Supported
SMB 3.0SupportedNot Supported
IPAMSupportedNot Supported
Cross-premise connectivitySupportedNot Supported
DHCP FailoverSupportedNot Supported
CPU ThrottlingSupportedNot Supported
Active Directory based AuthenticationSupportedNot Supported
Cloning virtual domain controllersSupportedNot Supported
DirectAccessSupportedNot Supported
Hyper-V ReplicaSupportedNot Supported
Live Storage migrationSupportedNot Supported


Server 2008 version had both 32 bit and 64 bit releases, however Server 2008 R2 started with migrating to completely 64 bit operating system releases for better performance and scalability, and Server 2012 completely is a 64 bit operating system. That’s where the future is heading in Microsoft Windows Server Operating systems.
IIS 8: Windows Server 2012 features IIS 8 which brings its latest version with features like script pre-compilation, granular process throttling, centralized certificate management, etc.
Power Shell 3.0: Power Shell is going to be the future of Microsoft. With Command line interfaces being less popular over the last decade, Microsoft is building up with newer versions of power shell with more advanced features and that’s where IT Professionals have to keep in mind and keep learning the new cmdlets.
Server Core: Server core was introduced in Windows Server 2008 as a competitor to Linux/Unix operating systems but with limited features. Microsoft is coming up with advanced features and with Server 2012 installation, it gives an option to switch to Server Core and vice-versa after the installation.
Direct Access: Direct Access was considered to be a replacement to VPN and was introduced with Windows Server 2008 but with Server 2012, it is much easier to use.
Hyper-V 3.0: Hyper-V introduces a new version 3.0 which offers an extensible virtual switch and live storage migration which is a step up from Server 2008 R2’s Quick Storage Migration to prevent downtime. It is also capable of migrating virtual machines (VMs) without shared storage.


SMB 3.0: SMB 3.0 provides improved performance of SMB Direct (SMB over RDMA), improved SMB event messages, helps Hyper-V live migration over SMB, and other new features which makes it a robust feature in Server 2012 R2.