> So, that 80-90% of the Fortune 500 is really just 1000 mainframes total. Generously, if every Fortune 500 had a pair in each geography (roughly EU, Americas, Asia for big corps), that ends up being 6, so 3000 globally, in production.
As others have posted, your estimates are WILDLY off.
First, fortune 500 companies dont own "two" mainframes, but a LOT more.
Next, many non-F500 companies own a lot of them as well.
Years ago I worked for a local cable company in Canada.
Not a "F500" company, owned at least two mainframes for the "head office" and each different 'subdivision' owned their own mainframe.
> Really just 1000 mainframes total.
I'd be willing to bet that any major city has more within its borders.
Even if OP's estimates are "WILDLY off", there still aren't many out there
Multiply his estimate to 1000 per F500 company ... that's only half a million
Put a pair in every major geography ... that's only 5,000,000
And, for kicks and giggles, multiply by another 10 for funzies
That 50,000,000
Yes, it's "a lot" ... but it's nothing compared to commodity hardware
According to a quick web search, Google alone had in excess of 1,000,000 x86 servers about a decade ago
That's one (large) company
I've worked with myriad companies who're running 10s or 100s of 1000s of x86 servers (let alone x86 desktops/workstations/laptops) - with nary a mainframe in sight (or maybe a couple ... which is on the order of "none" next to 100s of 1000s or millions of x86 boxes)
Per Microsoft [0], there are 1.4 billion Windows 10 and 11 devices (yes, I know that's not a server count, but it speaks to the orders of magnitude difference between x86 devices and mainframes ...even with my generous estimates posted above)
The flip side of that is that commodity hardware runs commodity software. It’s entirely possible to run a very large company without having any bespoke software.
Mainframes on the other hand or more likely than not to have software that only runs on a handful of machines at most.
So number of machines is not a good proxy for amount of software written.
On the other hand I’ve never touched a mainframe so it’s all speculation…
>So number of machines is not a good proxy for amount of software written.
It is a good proxy for the relative need of developers, however - with billions of x86 devices out there vs max a couple-few million mainframes...the scale of need is just wildly different
I don't know if iSeries (AS/400) counts as Mainframe... But the software stack is similar and I know that hundreds (if not thousands) of casinos run old Main Frame era software.
As others have posted, your estimates are WILDLY off.
First, fortune 500 companies dont own "two" mainframes, but a LOT more.
Next, many non-F500 companies own a lot of them as well.
Years ago I worked for a local cable company in Canada.
Not a "F500" company, owned at least two mainframes for the "head office" and each different 'subdivision' owned their own mainframe.
> Really just 1000 mainframes total.
I'd be willing to bet that any major city has more within its borders.