Bad numbers: another prediction of the mainframe’s downfall
Posted by: Mark Fontecchio
A recent survey from data center user group AFCOM reports a drop in mainframe use among 436 respondents, but analysts aren’t so sure, and if you add up the numbers, neither do the statistics.
Let’s take a look at the release:
“Only 39.6 percent of all data centers worldwide still operate mainframe computer systems today. In data centers that have mainframes installed, the median number in residence is two. And of all the data centers that have mainframes installed, 45.7 percent expect to replace one or more of them in the next two years. Of those that are expecting to replace their mainframes during the next two years, more than two out of three, or 67.1 percent will be replacing them with new mainframes, and 32.9 percent will be replacing them with high-end servers or other alternatives.”
That’s a mind-bendingly number of percentages so let’s break it down assuming a sample of 1,000 data centers:
- According to the survey, 39.6%, or 396 out of 1,000 data centers, are running a mainframe.
- Of the data centers with mainframes, 45.7% expect to replace one or more in the next two years. So 45.7% of 396 is 181. I will forget, for now, that there’s a chance a data center could replace one or more of its mainframes but still be able to keep the others it might have.
- Then the survey says that only 32.9% of those replacing their mainframes will actually be replacing them with machines other than another mainframe. So 32.9% of 181 is 60.
- So out of 396 data centers that are running a mainframe, 60 of them plan to replace one or more mainframes with a different platform in the next two years. That is 15%.
As you can see, when you take a percentage of a percentage of a percentage, the end percentage ends up being not as alarming as one might think. Especially if you consider that at least some percentage of non-mainframe users — even if it’s a small percentage — might consider moving to a mainframe platform in the next two years. That would cancel out some of the 15% leaving the platform completely, and lead to an even smaller number.
Is the mainframe in decline? I think that’s a good question. Two analysts give their take:
“Does the mainframe decline in the long run? Yeah, probably, but one of the big surprises of the last 10 years to most people outside of IBM is how strong the mainframe has remained,” said Illuminata analyst Gordon Haff.
“The numbers in this survey strike me as unbelievably high,” he said. “To have almost half of data centers saying they’ll replace one or more of their mainframes over the next two years, that’s a strikingly high number. High-end systems in general don’t turn over that quickly.”
Analyst Dan Olds of Gabriel Consulting agreed. “To find that almost half the sample plans to replace their mainframe in the next year or two just doesn’t seem to jibe with reality,” he said.
There are other opinions out there that the mainframe market will actually grow in the next few years, not decline. Just last month research firm IDC released a survey reporting increased investments in mainframe hardware and software in the next five years. In that survey, almost 50% of 300 end users — all of whom were mainframe users — surveyed said they plan to increase annual spending on the mainframe.
The study identifies the emergence of a blended, or hybrid, approach to computing on the IBM System z platform. “Customers are finding that new workloads, including Linux-based and Java-based workloads, can leverage the mainframe’s built-in security and high levels of availability, by running them on mainframe specialty processors, such as the IFL, zIIP and zAAP processors,” said Jean S. Bozman, research vice president with IDC’s Enterprise Platforms Group. “This pattern of adoption is placing software licensing costs on a lower price schedule for these new workloads than if they were running natively on the IBM System z hardware platform. In this way, customers are seeing a blended approach to deploying and maintaining workloads – carrying longtime workloads forward on System z, even as they bring new workloads onto the mainframe.”
In addition, a SearchDataCenter.com survey we did this year found that 74% of 352 data centers running mainframes were planning no change in mainframe spending this year. Meanwhile, 15% were anticipating some kind of increase, and 11% were anticipating some kind of decrease.
What do these seemingly contradictory reports tell us about the future of the mainframe? At worst, the mainframe is in a slow decline. At best, it’s growing. That seems to be pretty middle-of-the-road, vanilla results to me.


