Enterprise Linux Today: IBM z900 Mainframe Design Reflects New Linux EmphasisOct 04, 2000, 22:29 (6 Talkback[s])
(Other stories by Scott Courtney)
"If you had any doubt of IBM's commitment to Linux on its mainframe servers, Tuesday's announcement of the new eServer z900 platform should put those doubts to rest. The zSeries is the top end of IBM's newly-named eServer product line, and it replaces all existing System/390 processors. The eServer label is being applied to some of IBM's already-released hardware, so for some products today's announcement is mostly a rebranding. At the mainframe end, the z900 represents a totally new hardware architecture -- and IBM is pushing Linux as a core product to run on it."
"Although IBM claims full backward compatibility with all System/390 software, the z900 is a significant upgrade in performance as well as a demonstration of IBM's semiconductor prowess. The CPU is built onto a multi-layered ceramic substrate and each multichip module (MCM) contains up to 16 CPUs. There are about 31 integrated circuits inside the MCM and they are connected to one another and to the module's external I/O bus by over 1000 meters of gold wire. The transistor tally on the MCM's ICs tops 2.5 billion, so each of those 31 chips inside is significantly complex in its own right. The whole thing is about 12.5 centimeters square. The raw cycle time of the processor unit is specified at 1.3 nanoseconds, and general-purpose registers are 64-bit length as is the memory address bus."
"IBM claims approximately a 20-30 percent performance increase per processor over their S/390 "G6 model Z17" machine. In addition, the maximum number of CPUs per system has increased from twelve on the S/390 to sixteen on the z900. The math works out to about 70 percent faster at the top end of the z900, compared to the top end of the S/390. Of course, benchmarks like these are pretty synthetic and a lot depends on the operating system and the applications. In fact, IBM is claiming only 50-60 percent increase for the z900. Another aspect of performance is the system's ability to offload processing to specialized coprocessors, and here the z900 gains another edge...."