Q: What are Windows Server 2012’s scalability numbers?

A: Windows Server 2012 (formerly code-named Windows Server 8) will increase its scalability, supporting more resources than does Windows Server 2008 R2.

Below are the updated numbers compared to Windows Server 2008 R2 as disclosed at BUILD:

•Logical Processors - 640 (256 with Windows Server 2008 R2). Remember, a logical processor is a core on a processor (socket); or if the core supports hyper threading, then a logical processor is a hyper-thread, so a physical processor with 4 cores that supports hyper threading has 8 logical processors.
•Memory - 4TB (2TB with Windows Server 2008 R2)
•Number of hosts in a Failover Cluster - 63 (16 in Windows Server 2008 R2)

So what about Hyper-V in Windows Server 8? Here are the updated Hyper-V numbers:
•Logical Processors usable by hypervisor - 160 (64 with Windows Server 2008 R2)
•Memory usable by hypervisor - 2TB (1TB with Windows Server 2008 R2)
•Memory per VM - 512GB (64GB with Windows Server 2008 R2)
•Virtual Processors per VM - 32 (4 with Windows Server 2008 R2)
•Virtual Processors per host - 1024 (512 with Windows Server 2008 R2)
•Max active VMs per host - 1024 (384 with Windows Server 2008 R2)
•Max active VMs per failover cluster - 4000 (1000 with Windows Server 2008 R2)