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PC blades, virtual clients and zero clients

Barb Goldworm discusses why blade server technology is making a come back in the data center, and talks about virtual and zero clients.

As server virtualization has gained traction and IT staff have gotten comfortable with virtualization technology for consolidation and development/testing, many organizations are looking at expanding their usage from the server to the desktop. VMware's virtual desktop infrastructure (VDI) offers an architecture which includes a server component like ESX and/or VI3 along with a connection broker which connects either a thin client or a fat client (PC) to a guest virtual machine, resulting in a virtual client. The VDI architecture supports guest OSes such as Windows XP, Vista, Linux, etc., and will allow a user to connect to different VMs for different OS requirements (if allowed by IT through the connection broker).

Similarly, as organizations evaluate the move to Vista and the hardware requirements for large-scale Vista deployments, many organizations are re-evaluating their entire desktop strategy. VDI offers some significant advantages for users who require a full virtual client/desktop, but don't necessarily need their own physical desktop. VDI also allows a shift from a fully distributed software model to a model which offers central management over the virtual clients and the software running on them, since the software all resides within the servers in the datacenter. VDI is supported and, in fact, sold by major systems vendors such as IBM and HP, running VMware's ESX on their own back-end blades servers or rack servers.

PC/Workstation blades
Just as virtualization technology is working its way from the server to the desktop, so is blade technology. Following the model used by blade servers in a central chassis, a number of vendors offer PC/workstation blades which are inserted into a central blade chassis with individual PCs on a card/blade, and with the user interface (including the keyboard, video monitor, and mouse) "remoted" out to the end-user.

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The "remoting" of the UI can be done locally or over IP. Like virtual clients, PC blades offer a way to centralize the management of desktops and their software, while providing remote users a full desktop experience. PC blades have been around for several years, but are now making inroads into a more mainstream market.

Both HP and ClearCube have offered PC blades for a number of years. They have achieved strong success in vertical market segments where security and environmental issues made the benefits of PC blades worth a premium price. (In the past, PC blades were up to three times the price of an equivalent desktop. Today the multiplier is about 1.5.) PC blades are highly successful in situations where it is important to physically secure the PC and prevent removal and/or theft of data through removable disks or removal of the PC itself. The ability to lock the PCs in a central secure location, and only have the keyboard, video and mouse at the user location offers strong security advantages. Trading floors, for example, have been a huge area for PC blades. With high security issues and an estimated cost of down time of $7M/minute, the additional price of a PC blade is a drop in the bucket.

Environmental reasons also played a key factor in PC blade success. PC blades are a great option in areas where PC fans and blowers are not advisable, such as operating rooms. Also, places that are not conducive to computers due to vibration, heat, dust, etc. (such as manufacturing lines) are good candidates for PC blades. Over the past several years HP and ClearCube have done very well in these markets.

More recently, as prices have come down on PC blades and as users evaluate their overall desktop strategies due to pending decisions on Vista and VDI, PC blades are becoming an attractive option on a broader scale for various use cases, as part of an overall desktop strategy.

Significantly improved graphics
One of the issues that has been an impediment to PC blade adoption has been the performance in "remoting" graphics from the PC blade to the user location. This issue is a familiar one to users running thin client applications and/or terminal services applications. The higher the graphics function required, the slower the performance, making many applications unsuitable for remote operation.

A new player in PC blade technology, Teradici, has brought significant improvements here this year with a new chip pair used on both the PC blade and on the user KVM port, addressing graphics performance when remoting the user interface over IP. Teradici's technology is currently being used by ClearCube, Verari and IBM in their new PC/workstation blade offerings. Early demos of these products show graphics performance that is near-impossible to differentiate from a locally attached user interface, even running high definition video. Watch for the general availability release of these products later this year. Features and pricing vary with each vendor (e.g., single monitor vs. quad monitors, etc.) but all three are using Teradici chips for the high-end graphics options within their product lines.

The primary target markets for PC blades continue to be areas where they have been successful in the past – financial markets (especially trading floors), government (especially the federal government), health care, manufacturing and now insurance. With the advances in graphics performance coming from Teradici, PC blades are also expanding into additional areas like media (animation, movie making, entertainment) and into more general applications where users require a better user experience with multi-media - anything from YouTube to Vista Aeroglass. Other interesting areas include command and control for 911, airports, grid computing and lights out DR sights.

From a thin client to a zero client
Another interesting new player has recently emerged, introducing a new variation on both virtual clients and Teradici's two-ended hardware offering (blade and user port). In August, Pano Logic launched their zero client solution which uses a single hardware device acting as a user port at each desktop (the Pano) which communicates to Pano software and drivers running inside Windows virtual machines (the Pano Management Server and Connection Broker, and the Pano Service). The initial version runs with VMware Server and includes connections for a USB keyboard and mouse, a single monitor, audio in/out, an Ethernet connection and one additional USB device. The Pano is targeted for availability in late September. Although the Pano does not currently offer the graphics performance that Teradici delivers, it does offer an interesting alternative to thin clients connecting to virtual clients, requiring Pano hardware only at the desktop, and completely eliminating any client software at participating user desktops.

If you have any experiences with VDI, PC/workstation blades, and/or server-based computing/terminal services, including your successes and challenges or questions about how to determine which use cases are best for each technology, please email me at If you are looking for more information, and trying to understand the drivers, use cases, decision criteria, and overall landscape for desktop alternatives from PC blades, through virtual clients, terminal services and even application virtualization and streaming, watch for more columns here as well as the upcoming Focus Research Series on Desktop Delivery Alternatives.

About the author: Barb Goldworm is president and chief analyst of Focus Consulting a research, analyst and consulting firm focused on systems, software, and storage. Barb has spent thirty years in various technical, marketing, senior management, and industry analyst positions with IBM, Novell, StorageTek, Enterprise Management Associates, and multiple successful startups.

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