TOD Clock the same as the BIOS clock in PCs 3266
TOD Clock the same as the BIOS clock in PCs 3267
Speaking in terms of Mainframes, What is "TRUE UTC" mean? 1. What does this mean??? I am still lost like crazy here...When they speak in terms of setting the times as...
Shmuel Metz , Seymour J.
somewhat idle observation about memory contention ... but the 360-65 and 360-67 were essentially the same hardware with dynamic address translation (DAT) box added to the 360-67. The 360-67 could be run with plain vanilla os-360 operating system (w-o activating DAT) and it appeared to act in all respects like a 360-65.
the 360-67 multiprocessor was a different animal. it had provisions for multi-ported memory (processors and i-o access concurrently to memory). It also had a "channel controller" ... allowing all processors to access all channels ... something not seen again until 3081 with 370-xa.
the multi-ported hardware introduced about a 10percent additional memory access latency (but reduced memory contention). a 360-67 "half-duplex" running purely compute bound application ... had a "MIP" rate that was about ten percent less than a "simplex" 360-67 (or 360-65).
However, cambridge science center
had an opportunity to replace a 360-67 "simplex" with a 360-67 "half-duplex" ... running the identical same software, workload, and configuration. The "half-duplex" had approximately 20 precent higher processor thruput than the "simplex". This would appear to imply that on a standard 360 (65 or 67) that I-O memory contention could have possibly 30 percent impact on processor thruput (aka the "half-duplex" with no memory contention was nominally ten percent slower than simplex ... but under normal i-o load and memory contention, memory contention appeared to have slowed down a "simplex" processor until it was approx. 20% slower than "half-duplex" ... rather than 10% faster).
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