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?
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 systems do a lot more work per second than these old machines, while drawing less power. If you were to collect a large enough collection of mainframes to equal the performance of a modern rack server, you would need 10-1000 times the power to run the old stuff, depending on how far back you want to go - even 10 year old hardware can cost 4-10 times more in electric bill compared to a modern server with the same total performance level.
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Part of that is the racket that is software licensing for mainframes. Many vendors like CA7 charge based on the machines computational capacity. You can introduce soft limits or send usage reports, but not all vendors accept that to lower your price. Super expensive software costs, at least back when I worked on zOS.
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.
I used to operate an as400 mini frame from the 1980s and I want to say it it chugged close to a thousand Watts but I can’t tell you for certain, all I know is that when it was installed they put it on its own dedicated 15 amp line
I don’t know the exact numbers but: I frequently used a VAX11/780. Its main components were two enclosures (CPU and Memory), each about a square meter in footprint and somewhere in the range of 1.6m high (IIRC). Both had their power delivered as 3x380V (i.e. European three-phase power) into the power supply part (the lower half to 2/3rds of those blocks) which turned it into rock solid 5V - and a LOAD of heat, which meant the room also needed some extra strong AC.
That thing was an 8MHz cpu with 8MB of RAM.
huge power consumption… very expensive to run. i have regularly had access to take these things, but its like wanting to take home an old steam engine. its huge, expensive and to what end?
ha, they are run exactly as they were back in the day, thats half the point. no one wants to pay to replace(rebuild from scratch) that system.
Kind of “older”, i guess… the ones I have at work are from 2017. Each server has 36 10TB 3.5" harddrives and they’re the main power hog. Each server eats around 1.2kW. Each storage cluster holds four of these servers for a total of 1.2PB of storage space. The entire cluster is powered by a 5kVA UPS.
Quite power hungry, but pretty lean when compared to other methods for running that amount of storage.
Definitely power hogs. Modern switch mode power supplies are incredibly efficient.
I never really administered anything like that myself but I had a friend who took care of some old servers ~20 years ago in college. Multiple power drops in that small room went to fuse panels rated for several hundred amps each.
Unfortunately all I know were that they were VAX mainframes and were already considered obsolete in the late 90’s ;-)
Newer systems are way more power efficient than those of yester-year. Systems design and engineering, while built on the principles of the past, have very much changed just in the last decade alone. Older mainframe systems are really no better than museum pieces and technological curiosities today.
Are those older systems largely virtualized now? When you hear about some old system at a government office not being able to keep up, is it the same hardware?
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? ;-)
