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VDI “The Missing Questions” #1: Core Count vs. Core Speed

Choosing the right compute platform for your VDI environment requires both science and art. You have to balance CPU and memory characteristics against your expected workload profile and your desired density. At the end of the day, VDI has to meet some cost criteria in order to go from a fun science project to a funded program in your company. That means you can’t just throw the top bin CPU at the problem; you have to pick the right CPU. This is further complicated by the fact that there is not one CPU that is ideal for all VDI workloads. There is no magical bill of materials at the end of this series of blogs, but we will attempt to make your VDI decisions based more on science than art.

Strength in numbers? Or strength in speed? As Tony said in his introduction, we had several involved questions related to VDI that we honestly couldn’t answer… so we decided to start testing. This will be a series of blogs that attempts to answer practical questions like “when is processor A better than processor B?” And of course you then have to ask “when is processor B better than processer A?” In this first installment in the series, I will tackle the question of whether the number of cores or the core speed is more important when the goal is to achieve the best desktop density per host. Here is a handy guide to the other posts in this series:

The usual suspects. Throughout this series, we will focus on two processors. We picked them because they are popular and cost effective, yet quite different from each other. They are not top bin processors. Take a look at the table below for a comparison.

Note: Prices in this table are recommended prices published by Intel at http://ark.intel.com and may vary from actual prices you pay for each processor. The SPEC performance numbers are an average of SPEC results published by many OEMs (at http://www.spec.org/) across many platforms. These are not Cisco-specific SPEC numbers.

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VDI – The Questions You Didn’t Ask (But Really Should)

There’s no shortage of content out there (a quick Google search easily confirms this) when it comes to looking for vendor-originated material touting the latest server performance benchmarks for hosted virtual desktops.  Being part of that community, I’m pretty sure I have my fingerprints on more than one such piece of collateral – and I’m constantly reminded of this, when we run into questions along the lines of “yeah, {xxx} desktops on a blade is great, but c’mon, you and I both know we’d never do that in practice”.  It’s a balancing act of demonstrating solution performance, intersected with the practical reality of what IT managers would reasonably support in a production environment.

So what really matters?  If I’m implementing VDI for the 1st time, and I’m trying to make intelligent decisions around CPU, memory speed, IOPS, etc., where do I go?  VDI is unique in its consumption of compute, storage and network resources, when compared to other workloads hosted in the data center.  Much of the performance benchmarking info put out by server manufacturers is not specific to VDI performance, or how user experience might be impacted by simple decisions like choice of clock speed or # of vCPU.

Thankfully, there are folks in my company that care a LOT about such questions.  So much so, that a small, VDI-proficient group of them took it upon themselves to design and build an in-house lab environment with one express purpose – exhaustively exploring and documenting the performance and scalability impacts seen when configuring your compute platform for VDI.  No stone left unturned – things like CPU cores, clock speed, memory speed,  vCPU, memory density and more – all fair game.

The findings are extremely valuable to anyone deploying VDI, and what this team discovered is a set of real-life “questions”.  The “Missing” questions if you will – those questions that are noticeably absent or never sufficiently exposed in marketing materials, when it comes to the practical choices you can make that most significantly impact the cost, scalability and performance of your virtual desktop implementation.

So let me start with an introduction.  Over the next few weeks, you’re going to hear from some peers of mine – Doron Chosnek, Jason Marchesano, and Shawn Kaiser.  They’re Cisco Consulting Systems Engineers, and they live and breathe VDI (I know, melodramatic), as implemented in their customers’ data centers around the world.

They undertook this journey with the express purpose of answering the “missing” questions, by assembling a test platform in their lab, built on Cisco Unified Computing System (UCS), using readily available components including:

  • Various UCS B200 M3 configurations
  • Login Virtual Session Indexer (Login VSI) 3.6.1 benchmark
  • Login VSI’s Medium with Flash workload
  • VMware View 5.1.1
  • Microsoft Windows 7 SP1 32-bit virtual desktops
  • Pure Storage FlashArray with Purity version 2.0.2.

Keep in mind that their goal was not to explore maximum scalability, or prescribe a preferred design/architecture, or even what kind of server blade or processor you should use for VDI.  Instead they relied on commonly available gear easily found in our customer’s data centers.  If you want prescriptive design guidance, Cisco CVD’s are ideal for that, and you can find them here.

So let’s talk about their test environment.

Physical Lab

The physical environment shown below is a highly overprovisioned system.  Only one B200 M3 blade was tested at any one time, yet every logical link between elements shown consists of multiple 10-GbE links or multiple 8-Gb Fibre Channel links.

The storage array has 24 flash disks and is capable of substantially higher IOPS than used for this testing. All the infrastructure machines used for this test (Active Directory, VMware vCenter, VMware View, VSI Launchers) are virtual machines on the B230 M2 blade in the environment.

9 Q Figure 1

 

Note: At the time of testing, the Pure Storage had not completed UCS certification testing.

 

Logical Server Environment

9 Q Figure 2

The tests involved two UCS B200 M3 blades, one with dual E5-2665 processors and the other with dual E5-2643 processors.  The 2643 is a 4-core high clock/burst speed processor, and the 2665 is an 8-core medium/high clock/burst speed processor.  Here are the specs for the CPU’s chosen:

9 Q Figure 3

Now, you may wonder, are either of these THE processor you would choose for VDI?  Not necessarily! 

Keep in mind the goal we set out with – to expose the relative impacts of # cores, clock speed, memory speed, #vCPU’s etc.  What you’ll take away from the results, are guidance on which parameters matter for specific types of VDI deployments.  You can then safely look at a VDI-“workhorse” processor like the E5-2680 or E5-2690, and apply what our CSE’s have learned through this testing, to that class of CPU, and make your best selection there.

The tests were conducted using Login VSI’s Medium with Flash workload generator.  As we explore the test results in this series, you’ll see reference to “VSImax”, which defines the threshold past which the user experience will be unacceptable.  The VSImax threshold will appear on supporting graphs that show the performance curve under various test scenarios.  You can learn more about how this threshold is derived here.

9 Q Table 1

So that’s the test environment.  Through this series – let’s call it VDI – the Questions You Didn’t Ask (But Really Should) – our CSE friends (Shawn, Doron, and Jason) will explore and expose the findings they’ve documented for us, dealing with a new “question” each time.  If you join us for this journey, it’ll be worth your while – you’ll come away with a better appreciation of the impact that some simple decisions in your data center compute configuration can make.

So are you ready for the journey – You’ll find the Questions (answered thus far) below:

  1. VDI “The Missing Questions” #1: Core Count vs. Core Speed
  2. VDI “The Missing Questions” #2: Core Speed Scaling (Burst)
  3. VDI “The Missing Questions” #3: Realistic Virtual Desktop limits
  4. VDI “The Missing Questions” #4: How much SPECint is enough
  5. VDI “The Missing Questions” #5: How does 1vCPU scale compared to 2vCPU’s?
  6. VDI “The Missing Questions” #6: What do you really gain from a 2vCPU virtual desktop?
  7. VDI “The Missing Questions” #7: How memory bus speed affects scale
  8. VDI “The Missing Questions” #8: How does memory density affect VDI scalability?
  9. VDI “The Missing Questions” #9: How many storage IOPs?
  10. VDI “The Missing Questions” Conclusion

Special Web Event – You’re Invited!

If you’re enjoying our series, be sure to join our free webcast, where Shawn, Doron and Jason will discuss all the (Missing) VDI Questions Live + take your Q&A.  Access the webcast here.

Featured Whitepaper Now Available!

Need a convenient whitepaper-ized version of the discussion?  Download it now, here.

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CLOUD COMPUTING IS READY FOR YOU. BUT ARE YOU READY?

Previously I talked about the growing demands and how the role of IT has to change from a cost center to a business strategic partner.  And we also looked at the journey you need to take to deliver IT as a Service. Cloud computing is part of this journey and it is happening – and I mean all types of Clouds – Private, Public and Hybrid. In other words, we are entering the World of Many Clouds. Forrester Research recently published a report that concluded, “Cloud computing is ready for the enterprise… but many enterprises aren’t ready for the cloud.”1   Yet cloud deployments are happening, driven by workload virtualization and changes in application architecture and usage.

Take a look at this short video with Paul Perez (VP/GM of Unified Computing System and CTO of Data Center Group) and me. Paul shares his insights on the trends of how Cloud is changing the way of the IT and the challenges you will be facing.

Guess what? Once again Cisco is here to help you on your journey to the World of Many Clouds. How you ask?

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What’s New with VXI for 2013?

Desktop Virtualization the Cisco Way

Now that 2013 is officially here –  it must be time for the next wave of innovations for the Cisco VXI Smart Solution. The first of these enhancements is Jabber for virtual environments, which we are announcing today.

In 2012 we saw the 1000th customer deploy VXI to meet their desktop virtualization and VDI needs. You can read Phil Sherburne’s blog for a look back on 2012. Granted, these VXI deployments are not all 30,000 seat environments – they cover a complete spectrum of implementation scale, from small pilots to large production environments with tens of thousands of seats.

We recognized an interesting trend in 2012. Many IT departments were expanding on their initial deployments by simply adding UCS blades to scale the installed pilot VXI infrastructure – one of the great benefits of having a VDI architecture that scales seamlessly from zero to 5000 virtual desktops in just 30 minutes.

It’s rare for an IT department to roll out an enterprise-wide desktop virtualization deployment from day one. There are technology and operational lessons that are often best learned though a pilot production deployment numbering hundreds, rather than thousands of seats. With Cisco VXI we are assisting IT organizations with the initial pilots through attractive bundles that are targeted at pilot deployments, pre-production pilot service offers and the like.

However, once the pilot is successfully deployed, IT needs to consider how best to expand the deployment on three dimensions:

  1. Efficiently scaling the number of virtual desktops
  2. Supporting additional work profiles and use cases and
  3. Operationalizing the provisioning and administration of large deployments.

The VXI roadmap is well aligned with helping customers expand and scale their desktop virtualization deployments across all three dimensions.

diagram for 2.7 DC blog

Phase 1 of the roadmap has been focused on providing the most scalable, efficient and simplified infrastructure for desktop and application virtualization. Together with partners, including Citrix and VMware, we continue to expand on the capabilities of VXI in this area with greater virtual desktop densities, storage optimization, network and security enhancements – and the like.

In phase 2 of the roadmap we have been focused on expanding the use case support by enabling greater levels of mobility, broader device support and just as importantly greater support of integrated collaboration and voice/video services in a virtual desktop and application environment.

In the 3rd phase we will focus on helping enterprises and service providers enhance the operational efficiencies of large deployments through private, public and hybrid cloud workspace models.

Today’s “Jabber for virtual environments” announcement is squarely focused on enabling support for a broader set of use cases, by evolving our virtual workspace architecture. This important enhancement is part of a strategy for better enabling collaboration services on any device running a virtual desktop. This capability is enabled by software, called the Virtualization Experience Media Engine (VXME) that will initially run on Cisco’s thin clients followed by Windows thin clients and Windows PCs.

To learn more watch the webcast or take part in the conversation here

Also if you are going to be at Cisco Live in London at the end of the month –  don’t miss out on seeing the VXI technologies in action at the World of Solutions Data Center and Unified Workspace booths.

And finally, be on the look out for additional VXI developments as we progress through the rest of 2013.

 

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The Journey You Need To Take To Deliver IT As A Service

Previously I talked about the growing demands and how the role of IT has to change from a cost center to a business strategic partner.  It’s important to acknowledge that getting an organization to the point where it can implement IT as a Service isn’t easy, nor does it take place all at once.  Every customer has their own journey and different customers will take different journeys.  For some, it’s all about doing what they do now, only more efficiently or perhaps adding new capabilities. For others, it’s about making that full-blown transformation to service-driven IT.

So how do you get there? Each phase expands into a series of key initiatives…

It all starts with moving into more of a unified architecture of network fabric and corresponding operations.

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