It's less of a difference now, and somewhat unrelated to the specific topic, but...
A big historical difference with mainframes and data was the architecture around I/O. They always had separate processors to offload I/O, and I/O was always asynchronous. And things like VSAM were highly tuned to take advantage of that.
That's why mainframes continued to outpace Linux/X86 for some types of workloads...even after X86 performance far outpaced the main processors in a mainframe.
I believe that advantage is completely gone now, but mostly via brute force vs elegance. Commodity hardware is just so fast now.
Correct about the I/O. You can let the space-bar auto-repeat 1919 times, for instance (nearest equivalent to circling the mouse) and the CPU cost is... zero. When, exactly, do you think that the X86 surpassed the Mainframe processors, and in what particular way? Current generation (expect a new one this year) is 5Ghz (actually slower than the previous) and has lots of stuff. A fully-loaded box has a theoretical throughput of 30bn (yes, billion) RESTful transactions per day. And if that isn't enough power, you can hang another 31 boxes onto it and treat them as one.
"When, exactly, do you think that the X86 surpassed the Mainframe processors, and in what particular way?"
Fairly recently. Through things like affordable ssd, enough Moore's law around intel, and better distributed data stores. And better app side knowledge on how to break up a monolith.
I was around for a few failed "rewrite this TPF system" attempts and I saw what broke.
Commodity stuff can replace it now...but only very recently.
Or if you just meant x86-64 vs any other CPU, for the CPU alone? That debate is just done. They poured enough money into that mess that they won, assuming you don't care about power consumption.
Mainframe DASD is the same as "X86" disks, at least for those using "storage arrays".
Pretty much all the smaller Mainframes are gone, many years ago. I've not heard of any successful replacement of a loaded system which used fewer than three times the initial projection of "X86-power".
Anyway, time will tell. In 10 years' time you'll still think X86 is faster and there'll still be Mainframes.
As to your last line, who is "they"? I'm just interested. Thanks.
Sure, I wasn't trying to indicate there was no reason or benefit to mainframes, just to summarize the situation to make sure I understood it correctly. It does make sense to have an integrated library for advanced file access if you have dedicated IO hardware. That prevents a lot of misconfiguration of libraries that might try unsuccessfully use that system, if they even support it at all (i.e. OpenSSL and crypto hardware such as dedicated AES hardware as in the Via mini-ITX platforms of yesteryear).
A big historical difference with mainframes and data was the architecture around I/O. They always had separate processors to offload I/O, and I/O was always asynchronous. And things like VSAM were highly tuned to take advantage of that.
That's why mainframes continued to outpace Linux/X86 for some types of workloads...even after X86 performance far outpaced the main processors in a mainframe.
I believe that advantage is completely gone now, but mostly via brute force vs elegance. Commodity hardware is just so fast now.