Nehalem + XenServer = Performance!

Citrix has anticipated the potential for enhanced performance when using the new Intel Xeon 5500 with XenServer for some time now. We were fortunate to have received one of these gems from Intel in January to do our own comparison tests in our Bedford, MA test lab. We had just completed a series of performance validation tests for virtualizing SQL Server 2008 in a XenServer 5 environment (a very successful test series I might add...look for the technical WP on this shortly at: So we decided to keep the same test environment and repeat a portion of the SQL test series comparing Xeon E5405 vs. Xeon E5570-based XenServer hosts to see what kind of performance improvement we would get.

Each of the test servers were configured with a single SQL Server 2008 VM with 4 vCPU cores and 7GB RAM. We used DBHammer for SQL to create a 10 million record database and generated transaction processing workloads to simulate an actual SQL Server 2008 client workload. Workloads were created starting with 200 clients. Each client workload test ran for 30 minute periods. Starting after the first 10 minutes of each test, we began taking measurements using Microsoft performance monitor and continued doing so for the remaining 20 minutes of the test. Measurements of the maximum transactions-per second rate were taken every fifteen seconds until the 30 minute test period had elapsed. Increments of 200 clients were added until the maximum average CPU utilization level of 90 percent was reached. When average CPU utilization of 90 percent was reached, it was determined that the system was considered saturated and testing was ended.

Given the difference in the clock speeds of the two systems tested, 2.0 GHz and 2.93 GHz respectively, we fully expected to see some level of improved performance, but what we saw was pretty astounding, even to us. The Xeon E5405 XenServer host topped out at 1,600 clients, generating 13,708 maximum transactions per second. The Xeon E5570 XenServer host, by comparison, was able to sustain a load of 2,400 clients, generating 20,978 maximum transactions per second. That's an improvement of 53%!

Intel E5405 vs E5570 (640x443).jpg

The results are pretty clear. Not only is the new Intel Nehalem Xeon 5500 series a powerful addition to the Intel Server Solutions lineup, but it is a clear advantage to customers seeking to virtualize enterprise application platforms like SQL Server 2008 using XenServer.

Details of this comparison test will be posted in a whitepaper to on or about April 1.

Bernie Hannon

Director of Certification & Testing

Citrix Systems, Xen Products Division