dgrrrrr

In terms of cost comparisons, I don't have any raw data that I can share - so, apologies and feel free to take the number I stated with a pinch of salt.

In terms of security, z-series can be configured to meet the common criteria EAL 5 and beyond. Which is pretty d*mn secure and I don't believe can be matched by commodity hardware.

In terms of transactions per second, which is one of the most important metrics here, the z-series can cope with up to 1.1 millions per second. I believe the chunkiest single AWS instance maxes out at 10,000 tps.

Then there's reliability... a lot of these mainframe beasts have years, if not decades of up-time in a lot of cases.

On the downside, developing on them is clunky and there's a severe shortage of expertise. College graduates barely even know mainframes exist.

The labour! There's a severe skills shortage. The average age of a mainframe admin is about 95 years old!

I've recently worked with mainframes in a large, global organisation. Like the majority of people commenting here, I was sceptical about them.

The reality is, when it comes to transactions per second, reliability, security and vertical scaling - nothing beats them.

Also, it worked out about 60% less expensive to run a z-series for three years than it would've been to use a third party cloud solution.

So, yeah. Mainframes rock. And that's the reality of it.