6.5.1

Table Of Contents
For example, consider a cluster containing hosts with Intel Xeon 45 nm Core two processors that have been
set to the Intel Merom Generation (Xeon Core 2) EVC mode. A virtual machine powered on in this cluster
runs in the Intel Merom Generation (Xeon Core 2) EVC mode. If the cluster's EVC mode is raised to Intel
Penryn Generation (Xeon 45 nm Core 2), the virtual machine remains at the lower Intel Merom Generation
(Xeon Core 2) EVC mode. To use any of the features exposed by the higher cluster EVC mode, such as
SSE4.1, you must power o the virtual machine and power it on again.
Procedure
1 Select a cluster or a host in the inventory.
2 Click the Virtual Machines tab.
3 If the EVC Mode column does not appear, right-click any column title, select Show/Hide Columns, and
select EVC Mode.
The EVC modes of all running or suspended virtual machines appear in the EVC Mode column.
Powered o virtual machines and virtual machines that are not in EVC clusters show N/A as the EVC
mode.
Determine the EVC Mode that a Host Supports
By determining the EVC modes that the host can support, you can determine whether the host is compatible
with other hosts in an EVC cluster. For hosts to be included in the same EVC cluster, all the hosts must
support at least one common mode.
Procedure
1 Select a host in the inventory.
2 Click the Summary tab.
3 In the Conguration panel, expand EVC Mode.
The supported EVC modes are listed in order from the fewest to the greatest number of supported
features.
Prepare Clusters for AMD Processors Without 3DNow!
Newer generations of AMD processors do not include 3DNow! processor instructions. If hosts in a cluster
have dierent generations of AMD processors, some with 3DNow! instruction sets and some without, you
cannot successfully migrate virtual machines between the hosts. You must use an EVC mode or CPU
compatibility mask to hide the instructions.
The vCenter Server AMD Opteron Gen. 3 (no 3DNow!) EVC mode masks the 3DNow! instructions from
virtual machines. You can apply this EVC mode to EVC clusters containing only AMD Opteron Generation
3 hosts. Applying this mode allows the clusters to maintain vMotion compatibility with AMD Opteron hosts
that do not have 3DNow! instructions. Clusters containing AMD Opteron Generation 1 or AMD Opteron
Generation 2 hosts cannot be made vMotion-compatible with hosts that do not have 3DNow! instructions.
Prerequisites
Ensure that the cluster contains only hosts with AMD Opteron Generation 3 or newer processors.
vCenter Server and Host Management
130 VMware, Inc.