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And now, the Conclusion! VDI – The Questions You Didn’t Ask (But Really Should)

Back in January we launched a blogging series (with the above title) exploring the various server design parameters that impact VDI performance and scalability.  Led by Shawn Kaiser, Doron Chosnek and Jason Marchesano, we’ve been exploring the impact of things like CPU core count, core speed, vCPU, SPECInt, memory density, IOPS and more.  If you’re new to VDI and trying to avoid the pitfalls that exist between proof of concept and large scale production, this has hopefully been an insightful journey which has yielded some practical design guidance that will make your implementation that much more successful.

Here’s a snapshot of the ground
we covered along the way:whitpaper

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

What?  There’s a Whitepaper? (who doesn’t like free stuff?)

If you’re just catching up with us, and want a nice, complete, whitepaper-ized version of the series, this is your lucky day.  You can get download the paper here.

VDI No-Holds-Barred Webinar!

Finally, last month, as part of the series we also offered a webinar on BrightTalk, where our panel of experts walked us through these design considerations exposed in the series, and fielded audience questions.  It was one of those high quality interactions that hopefully provides great on-going usefulness to those who catch the replay.

If you missed the event, you can watch it here.  The guys fielded a lot of great Q&A from our community, and in fact there were a few lingering questions we didn’t have time to address during the event.  They’ve captured these for me (including their answers) provided below.

What’s Next?  Got a Question?

I hope the journey was as impactful for you as it was for me – I should point out that the guys are considering what to attack as part of the next phase of their lab testing.  I would highly encourage you to provide your input (or questions) be emailing us at  Let us know what’s on your mind, where we should take the test effort to better align with the implementation scenarios you’re facing, etc.  Thanks!


Q&A From Our Web Event:

1)      I have used Liquidware labs VDI assessment tool to help me understand how to accurately size my customer’s virtual desktops.  Should I not be using tools like these?

Answer:  These tools do a great job of looking at utilization on existing environments.  The potential issue is that most of these tools only aggregate MHz utilization, there is no concept of SPEC conversion to properly map to newer processors.  The other thing that we have seen with using this raw data and trying to fit it all in a particular blade solution is that there is usually no “overhead” of the VM taken into consideration.  So sometimes it looks like you can have a 20 Desktop to a single physical core on a server and that’s just too aggressive when you look at typical vCPU oversubscription, etc.  The bottom line is that these types of tools are great initial sanity checkers to validate the possibility of VDI consolidation.  If you are involved in these types of assessments and are working on a Cisco UCS solution, we have tools that can assist in importing this type of data and helping you make more pointed recommendation’s as well.  Just email and we can discuss!


2)      Do you find a performance increase/higher density hosts by scheduling similar vCPU count VM’s on the same hosts?

Answer:  We did not test the mixing of 1vCPU and 2vCPU workloads to technically qualify an answer to see that impacts this would have – but this is a great idea and we will definitely consider this in our phase 2 testing.


3)      Did you find giving more RAM to a VM caused the performance figures to decrease? E.g. 100 VMs at 4GM/VM compared to 100VMs using 1.5GB.VM

Answer:  Since our testing was a static memory allocation of 1.5GB, we do not have the data to answer this particular question – again, another great idea to possibly include in our phase 2 testing.


4)      Hi. A bit unclear on the last slide.  150 simultaneous desktops produce 39000 IOPs.  Is this assuming physical desktops and figures were based on IOPs on each physical desktop.  If so, I don’t see how the IOPs figure is relevant as it only on local disk, not SAN.  Think I misunderstood the last slide!!

Answer:  The 39000 IOPs was measured by both vCenter and the storage array controller as the total number of IOPs to boot 150 virtual desktops. No testing was done with physical desktops.


5)      Loved the Cisco blogs regarding vCPU, SPEC, memory speed, CPU performance.  Is there a similar piece of research that has been done regarding server VM performance rather than VDI?

Answer:  Not *yet….  Hint hint.  :)


6)      Are there unique considerations for plant floor VDI deployments?  The loads on those systems are typically higher on a continuous basis.

Answer:  Specific use cases for VDI with different workloads definitely do exist and you should definitely size based on those requirements.  If you feel your individual application requirements are not close to one of the pre-configured LoginVSI tests, the LoginVSI tool does allow for custom workload configurations where you can have it simulate working against your own apps.


Cisco Teams with The White House to Retrain American Heroes

Thousands of U.S. military personnel who have risked their lives in war have built technical, leadership and other skills while abroad. Despite risking life and limb, finding employment is a battle they’re often not prepared to fight alone. The realities of seeking employment that set in when veterans return stateside can be daunting.Cisco Teams with The White House to Retrain American Heroes

That’s why today we are joining forces with The White House, North Carolina-based Futures Inc., and key learning partners to aid veterans and service members who are transitioning out of the military.

Both Cisco and Futures Inc. are playing key roles in the pilot announced today with The White House directed at pairing transitioning military with high-demand IT jobs. We are honored to assume the lead in rallying the IT sector behind the initiative, known as the IT Training and Certification Pilot. This program takes advantage of Cisco’s WebEx collaboration technology to enable service members to participate in virtual interviews and leverage its partner network to provide opportunities for training, networking and successful new careers.

In an effort to leverage the unique skills, experience, and qualifications that military personnel hold, we are working with our partners Global Knowledge to deliver ANSI-accredited Cisco Training and Pearson VUE to provide the corresponding Cisco certifications that will allow transitioning military personnel to prepare for Cisco CCNA® certification exams and other globally recognized industry certifications for participants. Through the opportunities provided by the training program, participants will receive fast track training and IT certifications that will help address the nation’s workforce gap in IT jobs. We are delighted to be one of several IT companies working with U.S. channel partners and suppliers encouraging them to hire and train veterans.

Cisco is committed to helping offer a brighter future for the individuals who put themselves at risk for our country.

To learn more, please visit:

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White House and IT Industry Partnership Prepares Servicemen and Women for the Workforce

Approximately 1.2 million armed forces personnel are expected to transition from the U.S. military to civilian life over the next several years, with as many as 300,000 in the next 12 months.  Many of these veterans will look to move quickly into the next phase of their careers and need to find fulfilling jobs that will enable them to build upon their military experience and support themselves and their families. The Bureau of Labor Statistics reported a 10.1 percent jobless rate for post 9/11 veterans and exceeding 30 percent for veterans ages 18-24. It is imperative that, as a country, we come together to fix this. We must provide the training, certifications and jobs that our veterans have earned and deserve.

As an example of what we hope public private partnerships will do for our veterans who have given so much for our country, I look at Courtney Beard, a Cisco employee, who transitioned from active duty Air Force service in September 2011 with very little IT training. Coming from a family with a long history of military service, she knew at a young age that she would serve her country but she did not think much about what life would look like after she returned home. Highly skilled, and capable of excelling in the most difficult of circumstances, she still faced challenges finding a meaningful job aligned with her future goals; the process included resume critiques, regular attendance at job fairs, and participating in the Warrior to Cyber Warrior training and mentorship program with other veterans.

People like Courtney are the driving force behind the White House IT Training and Certification Program – an initiative to help transitioning military personnel make the difficult shift to the civilian workforce by obtaining the necessary training and certifications needed for high demand IT jobs.  Debuted today by First Lady Michelle Obama, the program – in partnership with Joining Forces and the President’s Military Credentialing and Licensing Task Force – will actively engage 1,000 transitioning military personnel in training, certification and career resources. The concept and platform behind the program was developed with leadership from Cisco and Futures, Inc. This public-private partnership exemplifies business and government working together to make a difference in our economy, our businesses and our country.

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Raise Your Hand

“Raise your hand!” It’s what we all have to do in order to grow our careers, gain new opportunities, and take on different experiences. Sometimes opportunities come to us without us doing anything, but most of the time, opportunities come across our plate because in someway or another, we raised our hands. We may have had a conversation about what we wanted to do with a mentor, or taken a class that seemed interesting, or directly said, ‘hey, I’m interested.’ Regardless, if we don’t raise our hands then we certainly won’t ever get selected for a new project, new job, or any new opportunities for growth. Read More »

Five Macro Trends that Benefit from Broadband Investment

Howard Baldwin - Photograph

By Howard Baldwin, Contributing Columnist

Much of the recent business and economic news has been uncertain, regarding the outlook for renewed growth. But I’ve been thinking positively about the upside opportunities for progress.

Let me indulge in a bit of crystal-ball gazing. The telecommunications industry spends a lot of time focusing on deploying broadband for current applications. It doesn’t take a lot of imagination to see that there are at least a handful of macroeconomic trends that are either going to boost broadband adoption — or wither because there isn’t enough broadband available.

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