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Monthly Archives: May 2007

SUN Uses VMmark to Measure X4600 Scalability

Our partners at Sun and AMD have used VMmark to produce an interesting virtualization scaling study of the Sun Fire X4600 Server. You can find a short version of the results at http://www.sun.com/servers/x64/x4600/VMScaling-Final3.pdf. A longer paper can be found at http://www.sun.com/servers/x64/x4600/VMScalability-wp.pdf.

One of the primary goals of VMmark is to provide appropriate data to customers as they design and build data centers to support virtualization. Studies like this one can help customers make informed decisions. Stay tuned as we continue working with all of our partners to make more information like this available.

Improved performance using Shared Folders in Workstation 6.0

It’s nice to see Workstation 6.0 being received well. We continue to focus on performance improvements for this product, not just the major subsystems but every feature we support too.  One of the significant improvements I’d like to draw your attention to is in using Shared Folders. Shared Folders allow sharing files between the guest and the host, or among virtual machines.

We’ve now wired up this feature with the guests’ kernel (page) cache. What this means is that your files in the shared folder will now be cached by the guest kernel for faster reads. Writes are done asynchronously, making them faster as well. The attributes (or metadata) of the files are cached, making browsing through your Shared Folder for all your files much quicker. This support is for Linux guests at the moment. With this integration you can expect improvements in performance up to 40%, depending on the usage.

We’ve always received great feedback on the usefulness of this feature, and we hope you continue to enjoy your experience in using Shared folders even more. We are looking into similar improvements for Windows guests as well.

Happy browsing.

Getting the best performance from Workstation 6.0

It was a proud moment for us when Workstation 6.0 went out the door.
While we continue to provide increasing flexibility in using desktop
machines and laptops, running multiple operating systems, and reducing
hardware costs, we’d like for you to enjoy the best performance you can
get from Workstation 6.0.

On top of all the goodness Workstation 6.0 has to offer, we now have a revised performance document as well. You can find it here.
We’ve tried our best to provide tips not only about things that you
could tune with Workstation and its features, but things you could
tweak on your host operating system and within the guest, and even what
to look out for on the hardware level. The reorganization of the
document makes it easy to find what you need to achieve the best
possible experience.

We also have a dedicated section in the performance document for
those of you who are interested in benchmarking with Workstation 6.0 or
in just understanding the performance you could get with it. This
includes recommendations on several benchmarks that you could use and
how to run them in a controlled environment so that the results are
understood easily.

We hope you find this document useful and that you enjoy your
experience using Workstation 6.0. Please tell us about your experiences!

Windows Vista Performance in VMware Workstation 6.0

One of the great new features in VMware Workstation 6.0 is its Windows Vista support. Vista can be used as the host operating system (HOS) and the guest operating system (GOS) for VMware Virtual Machines (VM). The question to us is how well Vista performs in VMware Workstation 6.0. This actually contains two sub-questions. (1) What is the performance of Vista as the HOS? (2) What is the performance of Vista as the GOS? To answer these two questions, we did a comparison of Windows Vista and Windows XP performance.

To answer Question (1), we ran experiments using the same virtual machine on the two different HOS’s (Vista and XP) and compared the results. We ran a set of workloads to measure the CPU, memory, disk and network performance of the VM. Vista host performance is on par with XP, except that Vista itself consumes more memory than XP. This means that Vista leaves less memory for the use of VM’s than XP.

To answer Question (2), we compared a Vista VM against an XP VM both on an XP host. We ran the same set of workloads as for the Vista host experiments described above. While Vista guest performance is on par with XP in most of our workloads, we did find a few cases that perform worse on the Vista VM than on the XP VM. To understand why Vista was slower in those particular cases, we conducted the same measurements on native physical systems, rather than on virtual machines. We found that Vista is slower than XP on native hardware almost to the same degree as on virtual hardware. This made it clear that VMware Workstation 6.0 wasn’t introducing any Vista-specific overheads, and that the relative performance on Vista is as good as on XP.

The chart below shows some representative results from our experiments. The bars represent the ratio of Vista to XP performance when comparing the Host OS, the Guest OS and native. The benchmarks shown are: gzip from the SPEC CPU2000 suite, PassMark PerformanceTest, Iometer disk workloads, Netperf networking send/receive, and boot/halt (time taken to boot and immediately halt the OS). The workloads had minimal variations from run to run, e.g. around 3% in performance.


In conclusion, Windows Vista works great with VMware Workstation 6.0! Go ahead and have fun with our cool virtualization technology!

VMware Workstation 6.0 supports both 32-bit and 64-bit Vista. Our conclusion here holds for both 32-bit and 64-bit.

Please refer to "Performance Tuning and Benchmarking Guidelines for VMware Workstation 6" for more information about Workstation 6.0 performance.

Multi-NIC Performance Tech Note Published

Networking performance is a critical part of the usability of any virtualized system. As such, several benchmarks have been published showing that a virtual machine can achieve near-native throughput. While this is a good result, it doesn’t tell the whole story. A shortcoming with most of these studies is that they use just a single 1 Gbps network interface card (NIC), which simply does not stress a modern system, virtualized or not. In an earlier paper, we addressed this by dedicating two NICs to a single VM and running an instance of netperf on each. This still was not a challenge. Now, in a Tech Note just published we used 3 NICs attached to a single UP Windows VM under ESX 3.0.1 and measured total throughput. This gives close to the maximum throughput possible in a fully-virtualized system. We compared this against native and the comparable configuration under XenEnterprise 3.2.0, the most recent version of XenEnterprise available. While both ESX 3.0.1 and XenEnterprise 3.2.0 yield near-native performance using one NIC, ESX gives considerably better performance with 2 or 3 NICs, demonstrating ESX’s lower overhead and better scalability.