Q: What are Windows Server 8’s scalability numbers?

A: Windows 8 Server 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)