Back to basics for a moment. A blade server is a single motherboard containing the CPU, memory, and networking and associated electronics. Don't think of it in the traditional sense of being a bolt-in board you'd find in a PC. For all practical purposes, a blade, although technically a motherboard, is card. Several can be installed, usually in a rack mounted enclosure, and they share hard drives, cabling, power supplies, cooling fans, and the like -all of the things that would need to be repeated time and time again in traditional PC-based server designs.
That's why blades are hot and sexy right now. Their dense packing lowers your square footage requirements, they decrease your power consumption, and the dense design and hot-swap capability keep downtime and maintenance costs at a minimum as well. HP explained this eloquently (based on a 48-server configuration) by noting that while its blade server would initially cost about $18K more than an equivalent Compaq DL320 server, projecting the 3-year costs of floor space and electrical power showed an overall $40K savings with a blade. This is why blades get as close to TCO nirvana as your accounting department is ever likely to achieve. Hewlett Packard's foray into the blade market shouldn't have been unexpected. Hot and sexy is what sells, and HP has been casting about for a hot niche it can turn into a profitable platform for a while now. Of course, you know that the blade market isn't barren of competition. According to HP, companies Sun, Dell,Compaq and IBM are not likely to ship competitive products until next year (though IBM is already marketing servers from RLX Technologies)--while a plethora of potential second-tier blade providers are just milling around, grazing and mooing.
Just to be sure it could live up to its own prognostication, HP did something atypical. Instead of developing its own proprietary design, HP created its blades with an open bus architecture: CompactPCI. This is a 7-year-old accepted bus standard that uses a 2mm pin and socket connector; the CompactPCI boards are inserted from the front of the chassis, with I/O exiting either through the front or rear. It's an industrial-strength bus that has found wide acceptance in a broad range of applications that require high bandwidth.
Then HP invited CPU manufacturers Intel, AMD, and Transmeta to participate, and opened the doors to a cornucopia of hardware and software suppliers to join the program. In theory, anyone can write software or build hardware for an HP blade--that's the allure of open architecture. Being part of the program, however, affords HP the luxury of being able to bless the product and not be caught by surprise by the inevitable calls for technical support. As well, knowing the players allows HP to use its Toptools management software effectively. Smart. Very smart.
But IT professionals know that every silver lining has a cloud. For HP, it's more of a fog that will dissipate over time. For example, for its initial release, HP's blade will be powered by Linux (Red Hat, Debian and SuSE). HP-UX and Windows won't show up until some time in the first half of 2002. While that's a major coup for the Linux-for-lunch bunch (and a tribute to Linux adaptability), put a red mark in the TCO column if you need to add someone who's Linux savvy to your staff.
Pentium III will be the processor of choice for the initial crop of HP blades. In fact, an Itanium blade won't be born until Intel reaches the third generation of its 64-bit CPUs next year. That's both good and bad news. You can continue to procrastinate about your move to 64-bit, but you can't even get the power of Intel's Northwood CPU in your blade server. Blades are focused on power savings, not necessarily power computing.
You could say that HP's one-CPU-per-board limit is a minus considering CompactPCI's 8-slot limit, but that's somewhat equivocal thanks to PCI-to-PCI bridges that will let you gang them. It does mean that an HP blade farm might occupy marginally more square footage than a competitive product that could employ a higher CPU density per blade. Let's leave this in the "it might be a red ink mark" column of the TCO ledger.
While those are the only apparent downsides, keep in mind that the plan works best if you're married to HP. That's how Toptools will seamlessly integrate your new blade with your traditional servers, and why your software and hardware will be blessed and fully supported. After all, the door to open architecture may be unlocked but the nameplate on the door does say Hewlett-Packard.
What's your take on HP's new blade servers? E-mail Bill or post your thoughts in our Talkback forum below.