IBM mainframe beats other platforms for cost and performance

We just paid just under $50k per server for on-prem physical servers that have 144 cores per server and 1.5 TB of RAM each.

For 12 of them it would be less than $600k and you'd get a total of 1,728 cores and 18 TB of RAM to compare against the mainframe's 30 cores and 2 TB of RAM for over 4x the cost!

That aside, samepage sharing has been a thing in virtualization for more than a decade. If you have 800 VMs running RHEL8 for POWER, a significant amount of the memory load is kept in identical pages, which lowers the burden of oversubscription. The recommended workload is unlikely to be 1000 unicorn/pet VMs, and more likely to be a large number of VMs running the same base OS, and some of the same workloads.

Synchronous interrupt locking is also a solved problem.

They’ve stopped being an innovation business.

Most applications don't need gigabytes of memory though? I don't know what one uses a mainframe for but web servers, file shares, remote login software, proxies, traffic scrubbers... lots of common applications use up to a few dozen megabytes of RAM; throughput is much more important there and memory to operate on is just for some state and buffers. Even a database with millions of rows and a dozen indexed columns, the index of that (I just checked a database of my own) is in the hundreds of megabytes, far from even one gigabyte.

It seems a bit odd to assume each server always needs multiple gigabytes of RAM.

> How would this IBM mainframe (or even the ancient vSphere 4.0 on blades) deliver any value over K8s and a cloud?

There value is in mitigating risk. The engineers want the new and shiny toys and for all the right reasons (development velocity, etc), but the managers fear change bc change == risk.

> Because cost-wise that would be the same, yet output-wise it wouldn't nearly deliver the value we would have had before.

Likely, you are right, but the budget committee will exercise some financial gymnastics in order to justify the outcome they want, instead of the budget dictating decision making.

> The only ones that are stuck are specialist cases or 'classic' multinationals.

Wrt banks, they are stuck on cultural inertia and risk mitigation.

Yep. My organization is trying to move away from mainframe and COBOL due to limitations in available personnel. The systems perform well, but that doesn't matter if we can't find people to keep them running.

A fast moving environment by definition would never even consider mainframe computing. And most places who would consider mainframes are already at whatever scale they will be at the conceivable future.

I used to work for a public healthcare company in the US that used mainframes extensively and when I was there we legally couldn't open any new locations. The only way to grow the business at all was to acquire existing ones, a multi-year process. So any changes or integrations typically had 12-18 months of lead time, and this was after everything was negotiated and signed. We typically heard about it a few months before that so sometimes up to two years.

And as you can imagine with the amount of red tape and regulation around healthcare, and the requirements around being on the stock exchange, change control was a pretty arduous process.

If the VM runs Linux, it's just Linux running on s390x. It's no weirder than ARM and has been on the Linux server market for far longer. I think you can install Linux directly on an LPAR. The part admins will need to learn is zVM, which isn't much more complicated than KVM or vSphere (and is much easier than K8s). The hardest part is the jargon and acronyms: IBM invented a lot of things that other manufacturers named differently.

> and the added 'special' sauce makes it incompatible with the broader FOSS ecosystem (including when "it really is the same as Linux on x86" - which it never is)

A mainframe usually can run Linux on zVM and it behaves just like a 5.2GHz VM with a very fast IO subsystem. From the top, it just looks like a very large computer that can run a lot of VMs in a single system. IBM started hitting diminishing returns with the number of cores and that's why core counts aren't increasing as they do on ARM and x86. Under Linux, the cores do SMT2.

> How would this IBM mainframe (or even the ancient vSphere 4.0 on blades) deliver any value over K8s and a cloud?

zVM is very mature technology and Z hardware and software have been coevolving for longer than most of us have been alive. More interestingly, you can partition your mainframe (into LPARs) and have several completely separated and isolated systems. It’s below zVM, so it doesn’t even suspect it doesn’t have the machine for itself. It's very common to run production, staging and development on the same system this way, as if you had three separate machines.

> 10 legacy developers?

Unless you plan to deploy your web app written in COBOL running on CICS and zOS, I'd suggest using different tools. If you already have systems running on zOS, you can easily access them from Linux VMs hosted on the same machine, through an imaginary network that's really fast (because it's not really a network).

> Because cost-wise that would be the same, yet output-wise it wouldn't nearly deliver the value we would have had before.

As the article points out, the mainframe itself is a little more costly, but the operational cost is lower. The convenience of having a single very reliable system instead of a cluster of less reliable ones can't be ignored. As Seymour Cray once said, it's better to plow a field with two strong oxen than with 1024 chickens.

There are downsides - IBM doesn't have these machines in stock the same way you can order a Dell, and ordering one is not a simple process - they'll build one for you, tailored to your needs. They'll probably deliver it with a couple extra CPUs so that when you need to upgrade it, you just pay the license and activate those resources.

One cool thing the z15 does is to activate all processors on boot to speed up the process. After the machine is running, the parts you didn't pay for shut down and the machine continues working.

No, it isn't clear. Show the benchmarks.

I don't think hyperscalers will ever care about this. They have millions of servers. They can just take the whole server out of commission as soon as it fails a health check. This is a critical difference between the mainframe model and the modern cloud model.

So like DynamoDB, Document DB, SQS, Service bus, and vast majority of managed cloud services?

Thats literally the entire reason to use cloud - to offload management of statefull services.

If I wanted just to run stateless docker containers, I can set that up myself on bare metal in a day.

These numbers don't make sense to me.

IBM is the only company that can sell you a fully licensed (you need a license to activate CPUs) IBM mainframe.

Starting with making a comparison on list pricing, when commodity hardware has huge discounts, mainframes don't. Then moving on to comparisons of running Oracle on a slew of tiny VMs with ~2GB RAM each. And, no benchmarks anyway, so what does "beats" mean?

I am pretty sure AWS for example doed not have major licensing payments for software. Their stack is mix of open source and self-written software and none of them require regular license payments.

So all the software costs that the study talks about would be reversed -- it is hard to compete with $0. And any extra work in system administration will be split over hundreds of thousands of servers.

You can’t just own one of something.

Plus, when you are at 95% capacity, your only option is to buy 100% more headroom.

You can run the latest zOS on Hercules/Hyperion, but IBM will not like it - and most certainly won't sell you a license. You won't be using a cool CPU, only a normal one pretending to be cool.

You can get a Linux VM from the LinuxONE Community Cloud. It's fun to play with - feels like a fast two-core (probably running SMT2 on a single one) with wicked fast IO but, apart from that, nothing too special. It has a lot of performance counters in the CPU too, so that's fun at least.

That's not what I observed. Maybe admins are more expensive, but I make a lot more as a Python person than I would be able to writing COBOL code.

iSeries (what they call the AS/400 these days) is not going anywhere soon. You can even get one from the IBM Cloud if you want to go cloud with yours. If you don't, you can still upgrade them. You can still run anything a first-gen CISC-based AS/400 could on the newest POWER9-based hardware (they are just pSeries with some hardware key that allows them to load iSeries OS).

They are not called mainframes though. They are midrange systems, the last remaining minicomputer breed. They are expensive, reliable, their OS is alien to most of us, but they don't get the mainframe badge.

You can get something similar (on a z15) for free from the LinuxONE Community Cloud.

I really thought they were going to do fully disaggregated clusters, but it looks more like vxblock-with-remote-management.