So what exactly are we to make of the IBM z10 mainframe introduced last month? Most of the reviews have been nothing less than stellar so far, with kudos going to everything from its cost and size to power and efficiency. But despite all its advances, is it possible that the z10 will simply be lord over an ever-shrinking enterprise domain?

Of course, it's hard to criticize the z10 from a technology perspective: a 64-processor quad-core design capable of replacing up to 1,500 x86 machines, serving a universe of perhaps 100 million users -- it's no wonder reviewers like Redmond Magazine's Stephen Swoyer are saying the z10 has "drastically altered the rules of the mainframe game."

Compared to the z9 mainframe, the z10 offers a much better platform for Web hosting and crunching large Java and Linux workloads, Swoyer reports. The 4.4 GHz processor speed in the z10 is more than double that of the z9, and computing capacity is bumped up 170 percent to 25,000 MIPS.

Virtualization and server consolidation have been one of the chief selling points for mainframes for decades, and the z10 continues this trend in spades. According to IBM's calculations, a typical virtualization platform could reduce a server farm from 760 cores down to maybe 304. While this certainly saves on hardware costs, when you add in related software and management systems, the total savings amount to about 26 percent. A single z10, on the other hand, would handle that workload using only 26 of its computing engines, cutting nearly 80 percent off the total system cost.

If mainframes like the z10 are aiming to turn the tide against distributed architectures, one of the main obstacles is their complex management structures. IBM has invested nearly $100 million to simplify its mainframe operating environment and is funding training programs at universities around the world to improve operator training.

Despite the predictions of just a few years ago, mainframes will continue to be the workhorses of large enterprises going forward. While these contracts will likely bring in big dollars, the real growth market is in small and medium-sized firms. And it's a pretty tall order to convince a 1,000-man shop to drop $500,000 on a mainframe when the same job can be handled by a four-socket Intel machine for $30,000.

The mainframe does have a future, but it's likely to be a limited one.