Cisco doesn't require you to run VMware's ESXi hypervisor, fully supporting Microsoft's Hyper-V and Citrix's XenServer hypervisors, as well as stand-alone operating systems including several flavors of Unix and Microsoft Windows.
However, we think that network and system managers should stick with hypervisor-based deployments on the UCS Express blade for maximum management capabilities and flexibility. With a hypervisor in place, remote operating system upgrades and replacements become simpler, and a hypervisor also opens the ability to easily run multiple virtual machines and get more use out of the UCS Express hardware.
We didn't look at performance in depth on the Cisco UCS Express blades because they're not really designed for compute-intensive environments. However, we think that for most branch office operations, including network operations such as file service, DNS/DHCP, proxies and other security functions, the UCS Express blade has plenty of power.
The UCS Express 140D blade we tested has three disk slots and a built-in RAID controller with RAID 0 (stripe), 1 (mirror) and 5 (parity) support. While Cisco allows you to put your own choice of 2.5-inch hard drives in the slots, they offer 7200 RPM SATA drives, 10K RPM SAS and self-encrypting SAS drives and speedy SSD options.
The result is a fairly speedy I/O subsystem that can deliver a terabyte or more of fast and reliable storage based on local hard drives.
For CPUs in the UCS Express blade family, Cisco has chosen the low-power version of Intel's powerful E3 and E5 processor family, but these are still very hefty processors. For example, the low-power Intel E5-2418L quad-core processor at 2.0GHz has about the same performance as an Intel Core i7 quad-core processor at 2.7GHz.
Combining this with a fast on-board I/O subsystem and, most importantly, plenty of memory makes the Cisco UCS Express blade perfectly capable of handling multiple virtual machines at the same time.
To test this, we used three different VMs: two simple Linux systems running CentOS 5.9 and a third running the open source Vyatta router. We fired up all three VMs and then used the iperf network performance testing tool on both Linux VMs to pass traffic through the third VM as fast as possible. Since the traffic was passing through four network interfaces, the maximum 600Mbps (without errors) we achieved translates to a total system throughput of about 2.5Gbps.
Meanwhile, CPU load on the UCS Express blade was only 21%, indicating that our UCS Express blade had plenty of firepower leftover.
The $64,000 question