1. A couple commenters have pointed out that software vendors do things differently. Perhaps so. The same is true on any/every platform, including "open systems." Fortunately you have choices.
2. A couple commenters have pointed out that mainframes can include different engine types. Yes, and that's hardware. First of all, see above regarding software vendors. (Hint: *Why* does IBM offer zIIPs? Spend a few seconds pondering that.) Second, so do "open systems." Intel has a VERY long list of "interesting" hardware features (or "features"). Let's consider a couple categories: (a) The Unified Extensible Firmware Interface (UEFI). UEFI features something called "Secure Boot." To summarize, even open source operating systems must be cryptographically signed with an unrevoked key in order to boot. Starting with Windows 10, Microsoft has "persuaded" the industry (OEMs) to make Secure Boot mandatory. This is quite controversial, it's fair to say. You don't have to "jailbreak" a mainframe just because you want/need to run a modified Linux kernel in an emergency, for example -- and it's probably not even possible to "jailbreak" Secure Boot. (b) Intel has an extraordinary amount of quite artificial "function tiering" in its product range: Atom, Pentium, Celeron, Core i3, Core i5, Core i7, Xeon, etc. And the company is dreaming up more market segmentation mechanisms all the time. These processors vary a great deal in the *expressed* instructions and other capabilities they have. Want to run your favorite virtualization software on an Atom series processor? Or your favorite cryptography on a Pentium, Celeron, or i3 series processor (with performance)? That probably won't work: the virtualization extensions aren't there, or the AES instructions aren't there, as examples. Too bad, Intel disabled them on your particular processor. Intel sets other limits on lower tier v. higher tier processors like memory expansion limits, cache limits, multiprocessor/socket limits, I/O bridge limits, and so forth. In recent years Intel has even reportedly tried to box out GPU manufacturers like NVIDIA and AMD by forcing onboard GPUs as part of their package and by making third party GPU interfacing at least more difficult. Intel operates an incredibly sophisticated, complex market segmentation and price discrimination regime, as Intel freely admits at least to its shareholders. (Full disclosure: I am one.) In comparison, IBM is a rank amateur in comparison with only four (configurable) main z processor types: CPs, CFs, IFLs, and zIIPs. (OK, you can count SAPs if you want.) And IBM just *reduced* the number from five to four with the discontinuation of zAAPs. I posit that the IT industry has flipped around in the past several years, and it appears that most people in this forum agree with me. That's gratifying. I was beginning to wonder if I was the only person observing the IT world flip. The word "open" should have real meaning, and it should be up-to-date, current meaning. UEFI, for example, is many things, but "open" certainly isn't one of them. -------------------------------------------------------------------------------------------------------- Timothy Sipples IT Architect Executive, Industry Solutions, IBM z Systems, AP/GCG/MEA E-Mail: [email protected] ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
