Fresh light on mainframe total cost of ownership reveals Big Blue's big iron is cheaper than a roomful of servers. Research house Illuminata's report, 'IBM System z TCO: Man Bites Dog' shows that running 10-50 applications on a mainframe costs less than running the same workload on a one server/one application basis where the servers run Linux or Solaris.

The report, written by Illuminata analyst Wayne Kernochan, (based on data supplied by IBM) states 'it no longer makes sense for the large enterprise to measure TCO strictly on a one-application-per-server basis.' It compared multi-application workloads running on one mainframe versus a bunch of blade servers or a set of 50 distributed servers. According to the Illuminata report IBM has demonstrated that mainframe total cost of ownership (TCO) advantages are 30 to 60 percent better than either 30 Sun Solaris servers or 300 Linux Servers.

Illuminata identifies several reasons for this about turn in mainframe TCO, including:-

-- a mainframe typically requires less electricity and air conditioning than many 1U servers running the same workload, because the mainframe has better cooling technology.

-- when running multiple applications the mainframe's people costs are much less than those needed to run the same workload on distributed systems. The report notes that, as a percentage of TCO, people costs have sky-rocketed over the past decade (from 14 to 43 percent), while hardware costs have shrunk (from 65 to 20 percent).

-- mainframe software costs are competitive with other platforms where workload levels are in the 10 to 50 applications area.

-- mainframe memory prices have fallen significantly in recent years.

The report sums this up by stating: "The mainframe has clearly seen substantial updates over the last decade, becoming more affordable, more attuned to modern APIs and middleware, and more network-savvy."

However, the idea that one server runs one application is going to be far from the norm in today's data centers where virtualization means multiple applications will run per physical server. VMware, Xen and Solaris containers are completely changing the server application landscape and server utilization levels are shooting up as virtualized servers run many more applications.

It is not clear if Illuminata has compared the TCO of multiple virtualized small iron, like blade servers, versus IBM's big-iron. Arguably it should as the TCO judgement in its study is likely based on a mainframe's ability to run multiple virtualized environments. This calls into question the effectiveness of the report.

Not surprisingly, IBM loves the contents and conclusions of the Illuminata report; Jim Stallings, IBM's System Z general manager, said: "The IBM System z mainframe offers a superior economic proposition for businesses with large or mixed-workload environments. The IBM System z's innovative architecture allows for breakthrough levels of TCO to meet the needs of business today."

The report's abstract states: "IBM recently conducted a series of TCO (total cost of ownership) studies suggesting that over the last three years, significant changes in the mainframe's TCO costs, taken together with changes in the typical computer workload, have led to mainframe TCO advantages of between 5 and 60 percent over typical Unix, Linux, and Windows alternatives."

It seems that IBM did not pay for the report however. A statement on Illuminata's website reads: "Our readers and clients can be assured that papers, presentations, or other content bearing the Illuminata logo represent the true opinions of Illuminata and its analysts. ... Illuminata's judgments and opinions are its own. We do not solicit or accept payment to endorse either products or vendors. We do not serve on the boards of directors of vendors, or accept equity payments."