Talk:ZIIP

Updates
There have been updates in eligibility for zIIPs. Shouldn't we list these and thus make the existing list accurate? Martin Packer 20:58, 27 October 2007 (UTC)
 * Yes, why not? :) --Kubanczyk 11:55, 28 October 2007 (UTC)

This and that
The page currently contains a lot of "the zIIP can be used for this or that". However this co-processor should be described more in terms of what and how it does things. What does the zIIP contain? An XMP parser implemented in microcode? Crypto-algorithms in microcode? Can that microcode be changed at runtime? These are questions interesting from a fundamental "understanding" i.e. technological point of view. What is the improvement versus say a machine code implementation of the same algorithms? Factor 10? Why not use a special purpose chip (f.ex. in metal TCP checksum calculation, MP3 decoders in HW etc.). Tomas Pospisek, 4th of March 2009 —Preceding unsigned comment added by 193.108.233.65 (talk) 09:38, 4 March 2009 (UTC)


 * This can be clarified: the zIIP isn't a coprocessor and doesn't have microcode that makes its functions run faster than on a standard CP, just as the zAAP doesn't run Java faster, and an IFL doesn't run Linux faster. Instead, they are financially different in that they permit increasing system capacity for targeted workloads without raising z/OS license fees. z10 EC Tech Intro page 9: "Important: Work dispatched on zAAP and zIIP processors does not incur any IBM software charges." The way it works is that a PU (processor unit) is "characterized" as one type of processor or another. z/OS doesn't run on an IFL, and only runs specific work on zAAP and zIIP - at the same speed but lower SW costs. Jsavit (talk) 20:00, 4 March 2009 (UTC)


 * The IBM z13 has simultaneous multithreading (SMT) functionality in its IFL and zIIP processors now, so workloads offloaded to the specialty processors can potentially have a performance boost compared to running on standard CPs. n2xjk (talk) 21:11, 5 August 2015 (UTC)


 * They always could, because zIIPs and zAAPs aren't limited by sub-capacity - they run at full speed. Philip Trueman (talk) 13:52, 12 February 2021 (UTC)