This is undoubtedly a step beyond the one-dimensional thinking CIO, but is still missing some very important information. While it’s true that the world’s biggest computing networks—Google, Amazon, Facebook, etc.,—run on commodity x86 server farms, there are huge costs associated with this. And once again, if CIOs aren’t careful to compare apples to apples (as opposed to oranges), they will be shocked to learn that they’re worse off than they were before a migration.

For example, if a CIO were to look at the costs on the mainframe side—hardware, software, monthly licensing, maintenance and upgrades—the result is a pretty big number. When planning for a migration, if that same CIO were to focus on only those items for a planned distributed computing replacement, the number might look pretty good. But it’s actually an apples-to-oranges comparison. What will be the difference in system reliability in terms of cost on a yearly basis? If the transaction throughput was properly considered (it often isn’t), what will that mean for yearly cooling costs? What about the extra personnel support costs for a data center full of servers, as opposed to one, two or three mainframe systems?

And that’s just the tip of the iceberg. This is akin to two-dimensional thinking in a three-dimensional world. The problem is that in a three-dimensional world, CIOs are still missing a whole lot if they're focusing on only two of three dimensions. Think about trying to figure out the mass of a cube of material by focusing on just one surface or an internal plane of the cube. You still just don’t have all of the information you need.

So for people like my friend Pete, that “x” variable is becoming a little better defined, but there’s still more…

Three Dimensional IT Thinking

This is the panacea, or the utopia of IT thinking. It seems obvious, but it is hard to do. The costs associated with mainframe computing are fairly well understood, especially when it comes time to pay the monthly bill, when the next revision of software is ready, or when it's time to upgrade the system hardware. But these costs don’t necessarily translate directly to distributed computing. There are similarities, like comparing hardware cost and software licensing per machine. But there are massive differences, too.

For example, if you discover you need twice as many servers as you planned the hardware cost is relatively insignificant, but the OS and software licensing costs could be quite significant, and will result in an unplanned and ongoing cost increase. It is the same for datacenter environment costs and personnel support costs. Three dimensional IT thinking means considering everything that will impact a migration project: the direct hardware and software cost dimension, the patch/update/upgrade dimension, the datacenter management dimension, etc., and much more.

Things that have a minor impact now may have a huge impact after a migration, and vice-versa. Project forward and estimate how the comparison will look after three years, when considering all aspects. Consider future upgrades, software updates, and maintenance. Consider the personnel costs associated with all this activity. Don’t let your biases blind you to important considerations. If you’re not sure, consult your vendor. But also consult third-party experts like Dr. Howard Rubin. Strangers on LinkedIn can help as some of them have succeeded in migrations just like yours, but many others have failed. Some of them maybe forthcoming. Take everything into consideration—that’s the secret sauce.

So, What is x?

So, that original question posed by my friend Pete: How many servers does it take to equal a mainframe?—now has an answer. The answer is still “x”— is a variable. But now we know that variable depends upon how you think about IT. Do you want to look at the big picture? Do you want to carefully consider all the variables, whether they’re expected or not? Do you have any biases? Are you willing to take another look at your plan, and another? Have you missed anything obvious? Do you fully understand everything involved in a comparison between mainframe computing and distributed computing? Are you sure? Are you willing to bet your job on it?

Answer all those questions to solve for “x,”

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