In this approach, most of the actual computing work will continue to be done on the desktop, not on data center servers. Pieces of the operating system and applications--only those needed to perform a function--are streamed from the data center over the network to the PC, but they'll be cached and processed locally, much like Web browser cache works. "If I'm an investment banker, and I do heavy-duty computing, ... I would almost never want to be on the data center server because if I'm in the data center, I'm sharing a server with all of the other users that are on that server," Birnbaum says.
That performance will be further enhanced by Merrill Lynch's use of a proprietary protocol, Spice from Qumranet, instead of the more common Remote Desktop Protocol, because it considers it better at transmitting latency-sensitive information such as voice-over-IP calls, Flash animations, and videoconferencing.
This should also work for mobile employees, who will be able to work offline by getting the entire operating system and apps cached on the local machine. Merrill Lynch is still working out the details; it's possible employees may have the OS fully installed locally but have apps streamed. Though the processing power is local, the cost advantage is that, since that PC checks for changes in the data center each time an employee connects, IT management remains centralized and automated.
This will be the new math of desktop virtualization, figuring out what computation happens on desktops versus the server, since it becomes so easy to move that work. For investment bankers doing complex financial modeling, a server doing all the work could only handle five to eight virtual desktops, versus as many as 35 for people using the Web and Word. "If I think about a $400 dumb terminal versus a $700 desktop, I tend to believe the desktop will prevail because that $700 is cheaper than a terminal plus a piece of the data center," Birnbaum says.
Why's all this happening now at Merrill Lynch? The company says it has the bandwidth to handle the increased network traffic, and PCs and servers have the computing power to offset bandwidth hiccups. Also, the software has matured to a point where the company can put together the pieces it needs to virtualize.
Virtualized desktops aren't supposed to change what Merrill Lynch employees see and do. But the company is ironing out some details. In this era of tech-savvy workers, what about applications people download and use that aren't centrally supported by IT? Stateless virtualization doesn't have an easy answer beyond saying no; since the local cache is temporary, there's no permanent location to save apps locally.
Birnbaum, for one, isn't unhappy about that, because those applications often interfere with other apps, cause performance problems, or open security holes. But he knows they have their place, so the likely answer will be a more streamlined process for approving new apps. Or there might be a way to create VMs just to give unauthorized apps an isolated, secure sandbox.
Birnbaum believes stateless desktop virtualization will make Merrill Lynch more agile in terms of growth, contraction, disaster recovery, and mobility. This year, the company is doing a big software upgrade for branch offices handling private clients, and it's a one-computer-at-a-time effort. In its virtual vision, that upgrade to provide new capabilities would happen once.
Merrill Lynch is ahead of most companies in desktop virtualization. Forrester's Lambert says she's just starting to hear companies consider such widespread deployments. But with this emerging technology, a wait-and-see approach could turn into a missed-the-boat outcome sooner than some expect.
Desktop Virtualization Drives Security, Not Just Dollar Savings