Information Technology organizations are finding that combining today’s industry standard servers based on multi-core processors with server virtualization can create highly efficient solutions. A series of tests were run comparing a Dell™
PowerEdge™ R900 server using new Intel six-core processors against previous generation quad-core processor servers. The Microsoft® Windows Server® 2008 OS with server virtualization Hyper-V™ technology was used as the basis with many virtual
machines (VMs) running on each of the servers tested. The results of these tests showed that the PowerEdge R900 with Intel six-core processors was able to outperform quad-core processor-based servers, with increased performance per watt efficiency.

Performance Advantage of Dell PowerEdge R900 with Six-Core Intel Processors Running Hyper-V: This link is to the complete white paper in PDF format. This TechCenter page provides the highlights from the paper and a place for comments and questions.


Table 1 provides the server configuration.

Table 1. Servers in the test environment

HP ProLiant DL585 G2 PowerEdge R900 Quad-Core PowerEdge R900 Six-Core
Virtualization software Microsoft Windows Server 2008 Enterprise with Hyper-V 1.0 Microsoft Windows Server 2008 Enterprise with Hyper-V 1.0 Microsoft Windows Server 2008 Enterprise with Hyper-V 1.0
Processor Four quad-core AMD Opteron 2.4 GHz 8358 SE processors with 512L L2 and 2 MB L3 cache Four quad-core Intel X7350 Xeon processors at 2.93 GHz with 4MB L2 Cache Per Core Pair Four six-core Intel E7450 Xeon processors at 2.4 GHz with 3 MB L2 Cache per Core Pair and 12MB L3 Shared Cache
HyperTransport / Frontside bus 1 GHz 1,066 MHz 1,066 MHz
Memory 128 GB (32x 667 MHz PC2-5300 DDR2 4GB DIMMs) 128 GB (32x 667 MHz fully buffered 4GB DIMMs) 128 GB (32x 667 MHz fully buffered 4GB DIMMs)
Internal disks Two Serial Attached SCSI (SAS) 73 GB, 15,000 rpm drives Two Serial Attached SCSI (SAS) 146 GB, 15,000 rpm drives Two Serial Attached SCSI (SAS) 146 GB, 15,000 rpm drives
Network interface card (NIC) Four 10/100/1,000 Mbps internal NICs Four 10/100/1,000 Mbps internal NICs Four 10/100/1,000 Mbps internal NICs
Disk controller Smart Array P400 PERC 6/i PERC 6/i

The Dell PowerEdge R900 and HP ProLiant DL585 G2 were connected to a dedicated Ethernet-based Internet SCSI (iSCSI) storage area network (SAN) with a dual-port Intel gigabit PCI Express NIC. The storage utilized was four Dell EqualLogic™ PS5000XV arrays, each with 16 146 GB, 15,000 rpm disks, for a total of 64 disks. Dell PowerConnect 5448 gigabit Ethernet switches were used for the iSCSI SAN. The EqualLogic Host Integration Kit’s Remote Configuration was used to configure the iSCSI settings such that only the iSCSI subnet and NICs would be used for iSCSI traffic. The iSCSI software initiator included with Microsoft Windows Server 2008 was used to connect through two NIC ports to the EqualLogic storage (see Table 2).

A RAID-10 storage pool with all four EqualLogic PS5000XV arrays was configured, and eight 200 GB volumes were created in this storage pool. With EqualLogic storage arrays the volumes are spread across the member arrays automatically to optimize performance. During this testing these volumes were the only active volumes, and they were spread evenly across the member arrays. Four volumes were assigned to the PowerEdge R900 and four to the ProLiant DL585. VMs were created and evenly divided across the volumes.

Table 2. Storage configuration for the test environment

Dell/EqualLogic PS5000XV
iSCSI Connections 3x 1 Gb/s per Array
Arrays 4x Dual Controller PS5000XV Arrays Each with 16x 146 GB 15,000 rpm disks (Total of 64 Disks)
Storage Pool 1 RAID-10 (With all four PS5000XV Arrays as Members)
Volumes (LUNs) Eight 200 GB (four assigned to each server)

Testing Configuration

To configure the systems to run Microsoft Hyper-V, both test servers were installed with Microsoft Windows Server 2008 x64 Enterprise Edition. The Hyper-V role was then added to enable the hypervisor. The version of Hyper-V that shipped with Windows Server 2008 was a beta so it was necessary to then apply the Hyper-V update for Windows Server 2008 patch, available from Microsoft’s Web site, which upgrades Hyper-V to the final version.

VM Testing and Configuration: To compare the relative performance of the Dell PowerEdge R900 and the HP DL585 G2 servers, a set of Windows Server 2008 VMs was created. An initial VM was created and then installed with x64 Windows Server 2008, and x64 SQL Server 2005 with service pack 2. The Hyper-V Integration Services were also installed in the VM that has drivers optimized for Hyper-V VMs. The medium-size Dell DVD Store ( approximately 1 GB database was then created using the scripts included with the DVD Store kit. The DVD Store database simulates the database back end of a simple Web-based storefront. The database size as setup for this test is small (approximately 1 GB) and representative of a database used for development or testing.

The initial VM was then replicated by using sysprep to first prepare the virtual disk for replication and then doing a simple file copy of the virtual hard disk. The virtual hard disks were evenly distributed across the LUNs assigned to the server on the Dell EqualLogic arrays. To complete the VM replication, new VMs were created and configured to use the new virtual hard disks. Table 3 shows the configuration for the VMs in the test environment.

Table 3. VM test environment configuration
Operating System Workload Memory Disk Virtual NICs Virtual processors
Microsoft Windows Server 2008 x64 Microsoft SQL Server 2005 x64 2,048 MB 18 GB 1 1

Performance and Power Consumption Testing Results

The VMs were run on the servers in successive tests, adding VMs in each round as described previously, until total processor utilization on the server reached 80 percent. A power meter attached to the servers measured the power consumption during these tests. Combining both the performance and power numbers allowed for a final calculation of performance per watt.

Performance and power consumption: Performance with a virtualized server can be measured in two components. The first is a sizing or capacity, which is the number of VMs that can be supported. This measure immediately leads to the second component, which is the aggregate performance that those VMs are able to achieve. The performance results from the testing are presented both in number of VMs and the sum of the associated performance, orders per minute (OPM) of those VMs.

The power consumption of systems has become a real issue for customers and needs to be considered as part of the overall server performance. An important factor when measuring power consumption is the configuration and load level of the server. The power numbers recorded and reported here are heavily dependent on the amount of RAM, number of PCI adapters, number of internal disks, and the amount of load on the system. All of the configuration options were kept as equal as possible between the systems for this reason.

The difference in the number of VMs and the OPM performance metric indicated the relative difference in performance. The test team calculated the performance results for the SQL Server 2005 VMs by totaling the OPM from all the VMs running in the test environment. Table 4 summarizes the performance results including the power consumption for the three servers tested.

Table 4. Workload performance results for each server in the test environment

Number of VMs Total Server CPU Utilization Performance in Orders Per Minute (OPM) Dell v. HP Performance Advantage % Avg Power Consumption (W) Performance Per Watt (OPM/W) Dell v. HP OPM/W Advantage %
HP DL585 G2 Quad-Core 26 80 % 58,355
739 81.0
Dell R900 Quad-Core 30 80 % 62,983 8 % 971 64.7 - 20%
Dell R900 Six-Core 40 80 % 74,084 27 % 864 85.7 6 %

These results show that the Dell PowerEdge R900 with six-core Intel Xeon 7450 processors provided a 27 percent performance advantage over the HP DL585 G2 with AMD Opteron quad-core processors and a 6 percent advantage in performance per watt. A second key finding is that by simply upgrading the processors in the PowerEdge R900 performance increased by approximately 18 percent, while power consumption decreased by 11 percent resulting in a 33 percent improvement in performance per watt.

The complete white paper is available in PDF format. Please use this page to ask questions or discuss.

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