I’ve never worked with major enterprise or government systems where there’s aging mainframes — the type that get parodied for running COBOL. So, I’m completely ignorant, although fascinated. Are they power hogs? Are they wildly cheap to run? Are they even run as they were back in the day?
A lot, just like today’s Mainframe and Super computers. They are calculating complex formulas and doing gigantic batch jobs, millisecond AI fraud detection etc. A regular computer or server will throttle a lot while they are designed to be loaded 100% of times. Dave Plummer of MS recently made a video of a 40TB RAM monster.
Did you ever look at how much today’s top of the line gaming rigs consume? ;-)
Not all mainframes are ancient; new models are still designed and sold to this day. And the brand spanking new mainframes may still be running COBOL code and other such antiquities, as many new mainframes are installed as upgrades for older mainframes and inherit a lot of legacy software that way.
And to answer your question: a mainframe is just a server. A specific design-type of server with a particular specialism for a particular set of usecases, but the basics of the underlying technology are no different from any other server. Old machines (mainframes or otherwise) will always consume far more power per instruction than a newer machine, so any old mainframes still chugging along out there are likely to be consuming a lot of power comparable to the work they’re doing.
The value of mainframes is that they tend to have enormous redundancy and very high performance characteristics, particularly in terms of data access and storage. They’re the machine of choice for things like financial transactions, where every transaction must be processed almost instantly, data loss is unacceptable, downtime nonexistent, and spikes in load are extremely unpredictable. For a usecase like that, the over-engineering of a mainframe is exactly what you need, and well worth the money over the alternative of a bodged together cluster of standard rack servers.
See also machines like the HP Nonstop line of fault-tolerant servers, which aren’t usually called mainframes but which share a kinship with them in terms of being enormously over-engineered and very expensive servers which serve a particular niche.
Modern hardware designed to run ancient software. Not all that special.
An older example that’s popular still is the as400. IBM replaced these but a lot of businesses refuse to acknowledge that and maintain these beasts sometimes paying more for parts than MSRP.
Interesting article that’s related.
https://www.gao.gov/blog/outdated-and-old-it-systems-slow-government-and-put-taxpayers-risk
If you ever talk with an insurance guy or system admin, you will understand why as/400 can’t be replaced that easily and most of the time people were unhappy with generic stuff replacing it.
Once while the split of IBM was on table, Microsoft was only interested in AS400 line. They used to do a lot of critical things on them. Yes, even Microsoft.
One can emulate AS400 since the entire thing including hardware and OS is a virtual platform from the start. I am not into financial/insurance/travel so I didn’t investigate if IBM offers a POWER or Xeon replacement. You won’t be able to explain throwing away millions of lines working code to move to some current fashion framework/language. These people make their money from 1/1000s of cents.
