More mission-critical applications are also migrating onto commodity servers and virtual machines. "Unix platforms were more expensive but considered to be more robust," Hull says. Not so much anymore. MasterCard is migrating more of its business-critical applications onto Linux and Windows x86-class servers, which it considers to be more secure and reliable than they once were, he says.
Competition among server vendors is also making transitions more tempting. It's a buyer's market, says Hillman. "The market is much more mature and more of a commodity than it ever was."
The big push toward using larger, scaled-up servers a few years ago has ebbed. "With cheaper, smaller boxes, migrating or replacing that [Sun E10K or IBM System p] - scaling out vs. scaling up - is the smart thing to do," Hull says. "You can do many of the same functions with six or seven smaller boxes that are a lot cheaper." That wasn't true five years ago, he says, adding, "We'll be doing more of that" type of consolidation this year.
Not every application on a mid-range system is a candidate for commoditisation or scaling out, but the trend is also putting downward pressure on prices for those proprietary Unix systems, says Hillman. "The commoditisation of servers is affecting the more traditional Unix systems," he says. "They absolutely are coming down in price."
New hardware needs
Virtualisation is also redefining server hardware itself, says Forrester's Staten. For example, IBM is seeing a surge in sales of four- and eight-processor systems, and the average revenue per machine has increased.
"[Customers] are plugging in all of the processors now, and a lot more memory than they used to," says Jay Bretzman, manager of product marketing for IBM's System x server line.
Hillman says GM's estimates of the ratio of CPUs to memory aren't holding steady. "We're finding that we need a lot more memory" to support the 10 to 20 Windows virtual machines or the four to six Linux virtual machines that GM is loading onto each physical server, he says.
Hull looks for servers that are workload-optimised. "Today you have specialty engines for scale-out and scale-up," he says. Even on mainframes, Hull says, MasterCard is migrating onto specialised processors such as the zSeries Application Assist Processor for running Java. MasterCard isn't alone: Many businesses are asking to see benchmarks of performance under specific workloads, says Rakesh Kumar, an analyst at Gartner.