While this article is supposed to be a history of big computers, this last entry is about a computer that is still being sold today. But it was sold yesterday too, and that's history, right? So, let's and take a look at IBM's biggest and baddest computer on the planet, the System z10 EC.
In this day and age, it's hard to imagine a physically large computer, but IBM did manage to create a 30 square ft. beast that weighed in at over 5,000 pounds and consumed 27,500 watts of power. Still not impressed? How about 1,520 GB of memory? Yes, that's a bit more than the 6 GB of most Core i7-based enthusiast boxes. Well, actually, that's a bit more than the average hard disk of a PC with the Nehalem. It can also have 1,024 ESCON, 336 FICON Express4, 336 FICON Express2, 120 FICON Express, 96 OSA-Express3, and 48 OSA-Express2 channels. That's more I/O than the X58, wouldn't you agree? Maybe several orders of magnitude more? This amazing machine can even host up to 16 virtual LANs in one machine.
Needless to say, these computers far exceed your normal server and, in fact, consolidate many smaller x86-processor machines. Rather than fading into oblivion, mainframes are finding customers that never used them before and wish to consolidate their x86 servers for space and energy savings. The flexibility of these servers are truly impressive, as one can stock them with up to 64 integrated facility for Linux (IFL) processors if Linux is the choice of operating systems or add up to 32 zAAP processors to assist with integration of Web apps using Java or XML with backend databases. There also can be up to 32 zIIP processors for data and transaction processing and network workloads, which are often used for ERP, CRM, and XML applications and IPSec data encryption.
The main processor, the z10 processor unit chip, has a rich CISC design that can execute 894 instructions, 668 of which are hardwired. The processor, in a nod to the ENIAC, even supports hardware decimal floating point operations, which can limit rounding errors and is much faster than using binary and converting. On top of all this, it can still run software written for the System/360, which is now 45 years old, and the amazingly solid MVS operating system, although it's now called z/OS. One can have up to 64 of these 4.4 GHz quad-core monsters running, designed for 99.999% uptime. It is no wonder these machines are selling well, as they offer incredible reliability, excellent and flexible performance, capacity that is hard to imagine, and very advanced, yet rock-solid software.
As suggested, virtualization capabilities on these machines are far beyond those of mere mortal servers. Naturally, they can run multiple operating systems, including Linux, z/OS (which includes a full version of UNIX), z/VM, and OpenSolaris, but more than that, they are capable of hot-swapping capacity non-disruptively and on the fly when one partition needs more capacity. One can even bring extra processors online for short periods of burst activity, and schedule them for certain times of the day, if there are known peaks.
These remarkable machines have capabilities that are so advanced that it might be difficult to get your mind around it. Forgetting for a moment the remarkable performance and flexibility of these machines, it is still dumbfounding how reliable they are. They feature, for example, something called "lock-stepping," when each result-oriented instruction is run twice and the results are compared to make sure they are the same. If they are not, the instruction is re-executed and the computer attempts to locate where the error occurred. It can even switch in-flight instructions to other processors, thus eliminating any negative effects of the error from the user’s perspective. More than this, when used in a parallel sysplex (clustering up to 32 mainframes into one logical image), one can update all the software and hardware on any mainframe without any downtime or disruption at all.
Only in the sense that these magnificent machines make the average desktop machine look small by comparison are they dinosaurs. They are far more advanced, powerful, flexible, capacious, and useful than the PCs we all know and love, not only in hardware, but in the incredible stability of the system software. They still are very much part of the backbone of computing and show absolutely no signs of death. On the contrary, their sales increase every year. In fact, how could it be any other way?
Mainframes arguably express man's highest achievement, not only in the amazing amount of thought and intelligence invested in them, but also in the sublime role they have had, and still have, on human life, and the endeavors of our kind. Perhaps rather than dinosaurs, they are like something even older. Like diamonds, they are a combination of many ordinary parts, that when combined in a certain way, through nature or extraordinary thought, become something far greater than the sum of ordinary.