VDI vs. DaaS: What is the difference, and which is best for your business' virtualization needs?

Desktop virtualization is nothing new, but now you have two popular forms to choose from: VDI and DaaS. There are distinct differences between them, and knowing what's what is important if you're looking to invest.


Anyone who's spent much time in an enterprise computing environment has played with a virtual machine at some point. Up until recently local VDIs were the standard, but today's bandwidth availability and cloud options make desktop-as-a-service (DaaS) much more practical--though still with some limitations.

What's a VDI?

Virtual desktop infrastructure (VDI) has been around for a long time and traditionally was the only way to run a virtual desktop. Slap a server in the datacenter, load it up with virtualization software, turn on some machines, and you're good to go.

Since VDIs are centrally located the IT team is responsible for managing them. That means the hardware, software, licensing, and deployment are all handled in-house. Latency is minimal, the IT department has complete control, and even if access to the internet goes out work can still get done.

But that's not to say VDI doesn't have its drawbacks. While it's convenient to manage hardware and software internally VDI systems require dedicated IT staff to handle all possible contingencies. Hardware failure, software issues, and anything else that could go wrong has to be handled in-house, and that can get expensive.

What about DaaS?

DaaS, as Citrix's Kenneth Oestreich said, is "VDI that's someone else's problem." At its most basic level that's true: DaaS is a VDI that is hosted in the cloud by a company like Citrix, Amazon, or Google. With DaaS all of the hardware is managed by the provider, so you won't have to worry about rackspace, hardware breakdown, or maintenance.

DaaS systems are subscription based and are generally charged by seat. It can be tempting to rush into a DaaS system to clear the clutter of a datacenter and the calendars of IT staff, but there are quite a few reasons why that may not be the best idea.

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"There are two types of DaaS providers: those that give bare bones systems and those that are business ready," Oestreich said. Most DaaS providers offer the most basic of systems that only come with standard Windows software. Anything users need to do their jobs still has to be supplied and configured by the IT department.

Is the DaaS revolution upon us?

Infrastructure, software, and computing platforms are all increasingly being hosted in the cloud, so surely desktop computers are only a step away, right? Not necessarily, at least if you ask Nathan Hill, mobile and endpoint computing research director at Gartner.

Long term pricing, Hill says, is a major impediment to greater DaaS implementation. "The pricing of DaaS can often be misleading, as the entry point price ... often covers a very light resource profile for not much more than OS or workspace hosting."

Hill said that DaaS is great for agile computing needs, but as a replacement for the average employee's desktop it isn't going to always fit the bill. "To replace a permanent desk based employee today is invariably going to result in a higher total cost of ownership, so the question becomes can organizations justify increased investment for the agility the platform can bring," he said.

Who can make DaaS work?

Both Oestreich and Hill agree that business-ready DaaS systems can benefit certain kinds of organizations. Schools can use DaaS for student computing in labs and as follow-along training tools, temp workers can be given a workstation without hardware setup, and anyone needing to test hardware and software profiles can benefit from a completely cloud-based system.

Oestreich said that Citrix partners offering vertical integration have had success, which he sees as the eventual path of DaaS offerings. Partner companies like Simplified Innovations, Approach Technology, and TekLinks all offer industry-specialized DaaS platforms, and they continue to grow rapidly. These specialized providers can offer industry-specific software bundled right into DaaS machines, taking all the licensing and implementation out of a company's hands.

Why you should wait

"When you add all the service components for a fully managed service," Hill said, "DaaS can often climb to $100 per user per month or more." The cost, he says, is one of the biggest reasons why VDI isn't going to vanish overnight.

The initial investment in DaaS can seem cheap, but that's for the most bare bones system. In those cases IT staff are going to still need to manage software installation and VM deployment. Couple that with costs in the hundreds per seat and you might not save any money.

SEE: Cloud computing: We'll never be all in, say most companies (TechRepublic)

Think of local VDI systems as a car you've already paid off: all you need to worry about are maintenance costs. A new car might seem appealing, but the monthly fees can quickly outpace the annual cost of repairs on the older model. Likewise, a large chunk of cash spent on VDI servers might seem like a lot, but spaced out over a year it's much more affordable.

"DaaS is a commodity," Oestreich said. "A lot of businesses spend time chasing prices for no more advantage over a locally installed VDI." To get the maximum benefit out of DaaS a business needs to invest a lot of money monthly, and then there are still problems of latency, data hosting, and regulations.

Fields like government, healthcare, and financial services can't always adopt DaaS simply because vendors aren't compliant with industry standards. While that's changing, it's going to take time. Hill suggests that IT staff monitor the changing face of the DaaS market, and when considering a move think about the benefit to specific employees, not the whole organization.

There's not one good answer

DaaS is still a newer technology, and it's growing along with the rest of the XaaS world. In the future it's entirely possible that work desktops will all be thin clients connected to the cloud, but we're not quite there yet.

"The reality is that VDI and SBC as technologies are more mature than DaaS," Hill said. Keep an eye on the industry, but don't be ready to dive into the deep end just yet.

The 3 big takeaways for TechRepublic readers

  1. DaaS can seem like a tempting new technology, but it's not for everyone. Heavily regulated fields should avoid it for now and stick with VDI solutions.
  2. DaaS might seem more affordable, but don't let a low price tag fool you: the cheaper it is the fewer features you're getting. Heavy processing power won't be there, and IT staff will still need to spend a lot of time managing VMs.
  3. If agility and flexibility are your biggest concerns DaaS may be a good bet. Don't jump in, though: take a look at the industry and fully explore your options before considering a transition.

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