On the low-end. Ever shopped at Costco? It's all IBM AS/400's handling the back-end. That's why all their Windows 11 PC's have big black and green terminal apps running front and center

On the high-end? Banks, airports, hospitals, research labs. There's a lot of places that need the kind of fault tolerance that specifically IBM POWER systems provide

EDIT: Okay, IBM POWER "systems". They've been described as mainframes to me so I went with that terminology

▲

nabla9 a day ago | parent | next [-]

IBM Z mainframes use Z processors and now Telum, Telum II processors, not POWER.

▲

inkyoto a day ago | parent [-]

z Series have used both, POWER and TELUM (I and II) processors.

For many years, the 64-bit extension of the original S/360/370/390 architecture was emulated in the software layer via the static binary translation – just like the i Series AS/400 have been doing since the inception, and there was no native S/360 implementation in silicon for a fairly long time.

If my understanding is correct, with TELUM processors, IBM has gone back to implementing the ISA in silicon, although the available details on TELUM are scarce.

▲

ch_123 a day ago | parent | next [-]

This (and variations) is commonly believed but not the case - IBM's Z hardware has always used processors which natively implement the Z instruction set. I think part of the source of the confusion is a presentation from years ago which showed that some IP is shared between the Z and Power CPUs.

	▲	sillywalk 14 hours ago \| parent [-]
		> a presentation from years ago which showed that some IP is shared between the Z and Power CPUs. The eCLIPz project, for the POWER6 & Z10[0]. "The z10 processor was co-developed with and shares many design traits with the POWER6 processor, such as fabrication technology, logic design, execution unit, floating-point units, bus technology (GX bus) and pipeline design style, i.e., a high frequency, low latency, deep (14 stages in the z10), in-order pipeline. However, the processors are quite dissimilar in other respects, such as cache hierarchy and coherency, SMP topology and protocol, and chip organization."[1] [0] https://news.ycombinator.com/item?id=18494225 [1] https://en.wikipedia.org/wiki/IBM_z10

▲

nabla9 a day ago | parent | prev [-]

Your understanding is not correct.

IBM z15 mainframes had z15 chip now they have Tellum. z chips are their own line. z14, z13, ...

▲

wolf550e a day ago | parent | prev | next [-]

"mainframes" are z/Architecture, not POWER.

	▲	a day ago \| parent [-]
		[deleted]

▲

gosub100 a day ago | parent | prev [-]

I seriously doubt there's a POWER mainframe in the back of Costco to handle the 3 UPC barcode scans per second. It's possible that every Costco store funnels its orders to a single mainframe somewhere.

I think a more realistic case is the visa and MasterCard credit card networks that have almost 0% downtime.

▲

robotnikman 10 hours ago | parent | next [-]

I can provide some insight into this. Most stores will have a server which handles the barcodes, pricing, etc, locally. Then all transactions are usually sent in a batch everyday from the store server to a central server/servers somewhere for processing, usually around that time reports are also generated and stats made available for BI analysis.

Payments processed by the payment terminals handle the authorization of the payments separately from any store servers, usually through a service such as Connected Payments.

▲

dardeaup a day ago | parent | prev | next [-]

No such thing as a POWER mainframe. IBM's POWER lines (i and p) are different from their mainframe line (z).

▲

CursedSilicon a day ago | parent | prev | next [-]

Not a POWER Mainframe, no. But AS/400's come in many sizes. The smallest ones are roughly the size of a standard workstation

▲

pjmlp a day ago | parent [-]

Back in 1994, they were small enough like a big PC tower, I used to seat on one occasionally, that was out of order.

One of my Summer intern jobs was to run backups every few days on a AS/400 system.

That "seat" was the old one that was yet to be collected.

▲

RaftPeople a day ago | parent [-]

> Back in 1994, they were small enough like a big PC tower,

Back then their model lineup ranged from the small size like you mention to approx 3 or 4 refrigerator size at the high end.

When I did some system work out at Costco in the 90's they had 4 of the largest models connected together in one system image (sysplex I think).

	▲	pjmlp a day ago \| parent [-]
		Indeed, never saw other sizes in real, only on magazine ads.

▲

gt0 a day ago | parent | prev | next [-]

Mainframes are not POWER, they are z/Architecture.

For AS/400 (IBM i), they're POWER, but come in pretty small models like IBM Power S1012, it's available as "deskside", i.e. a big tower.

▲

chiffre01 a day ago | parent | prev [-]

I think it's more likely they have a rack of IBM iSeries servers in the back someplace, or maybe in a colo data center.