RemoteFX and Hyper-V–How can I verify if “SLAT” is working?

RemoteFX and Hyper-V–How can I verify if “SLAT” is working?

By Ramazan Can [MVP Cluster]

SLAT (Second Level Address Translation) is going to be more important since VDI and Remote FX scenarios and currently there is no point where you can identify the capability of SLAT from your CPU processors.

On Intel processors, SLAT is called Extended Page Tables (EPT), and on AMD processors, it is called Nested Page Tables (NPT).

The only way how you can verify that SLAT is working is via performance counter “Hyper-V Hypervisor Root Partition” –> Address Space. In non SLAT environments the counter is permanently higher than value “0”.

Add Performance Counter:

SLAT enabled System, where value is “0”:

non SLAT capable system, where value is permanently “80”:

SLAT is an CPU hardware requirements for using RemoteFX with Windows Server 2008 R2 SP1 in Hyper-V – especially VDI – scenarios:

SLAT-enabled processor The processor in the RemoteFX server must support Second-Level Address Translation (SLAT). In virtualization scenarios, hardware-based SLAT support improves performance. On Intel processors, this is called Extended Page Tables (EPT), and on AMD processors, it is called Nested Page Tables (NPT).

ref: http://ramazancan.wordpress.com/2011/02/09/hyper-vhow-can-i-verify-if-slat-is-working/