Specifications

A Principled Technologies test report 2
Cisco UCS B200 M3 Blade Server:
Uncompromised virtual desktop performance
MORE VDI SESSIONS ARE BETTER
Choosing the right combination of hardware and software for your virtual desktop
solution can significantly affect your bottom line. A robust hypervisor, top-of-the-line virtual
desktop software, and a server built on powerful processors with an expansive memory
footprint all work together to ensure you can meet the needs of your employees without your
spending money, space, and time on additional hardware. The greater your virtual desktop
density, the fewer physical servers you need. This reduces your electricity usage and power
costs, and results in a greener datacenter.
We set out to examine such a virtual desktop solution, one that consisted of the
following components:
 Cisco Unified Computing System™ (UCS) B200 M3 Blade Server with Intel®
Xeon® processor E5-2690s
 VMware vSphere 5
 Citrix Provisioning Services 6.0 Flex Cast Streamed VHD delivery model
 A Citrix XenDesktop 5.5 virtual desktop pool consisting of 191 Microsoft®
Windows® 7 x86 VMs
 191 total virtual desktops used to determine a Login VSImax of 182 desktops
with an acceptable response time, all provisioned with 1 vCPU and 1.5 GB of
reserved memory
 EMC® CX-3 storage array
For details on test settings, see Appendix B.
RESPONSE TIME MATTERS
After all desktops are idle, Login VSI incrementally logs users into virtual desktop
sessions and begins workloads on each. Login VSI measures the total response times of seven
typical office operations from each session and calculates the VSI Index by taking the average
response times and dropping the highest and lowest 2 percent. The average response time of
the first 15 sessions determines a baseline; the Dynamic VSImax is baseline x 125% +3000ms. As
more sessions begin to consume system resources, response times degrade and the VSI index
increases until it is above the Dynamic VSImax. When this condition is met, the benchmark
records a Login VSImax, which is the maximum number of sessions that the platform can
support. Because the VSI index drops the highest 2 percent of response times, we needed to use
191 virtual desktop sessions to reach the Login VSImax of 182 for the Cisco B200 M3. Figure 1
shows the VSI index average and average response times for all active sessions recorded during
the test. The Cisco UCS B200 M3 Blade Server was able to support 182 virtual desktops based on
the Login VSImax assigned by the Login VSI benchmark. User response time degraded only when
all 16 cores were nearly saturated.