On Thu, 20 Jul 2023 at 02:15, Jon Perryman <[email protected]> wrote:
> > Why do that. It would result in a huge loss of hardware revenue. > > IFLs for running UNIX are much cheaper than the CPUs needed to run z/OS. > > IFL's are discounted because Linux runs poorly on z16. Every CPU in a z16 > is the same so IBM will never discount an entire z16 just for Linux. Linux > customers don't want z/OS so z16 is not an option for Linux only customers. > If IBM wants to increase the z16 market share, they must make RHEL perform > as well as z/OS and charge full price for CPUs. It would be interesting to see your evidence of IBM Z not performing well with Linux. That was probably true 20 years ago with the early CMOS CPUs, but not anymore. My experience is that z16 CPUs are very effective running enterprise application workloads in Linux at high levels of utilization. IBM contributions to the various open source projects like the gcc toolchain let you generate code that is optimized to take advantage of the CPU architecture, the zlib compression library takes advantage of the built-in compression instruction, the openssl libraries exploit CPACF instructions when compiled for s390x, java applications in Linux and in z/OS compete well with other platforms, the entire machine learning suite exploits the built-in neural network instruction of the Telum chip. Pricing is too complicated for techies. You get a CPU rather than IFL to run licensed IBM software, which suggests that the price difference for the hardware is for operating system software revenue not recovered by MLC. The same holds for the other specialty engine types that run workloads that do not have to contribute to the operating system software revenue; java runs as fast on a zIIP as on a CP, so that's no reason for the rebate on a zIIP. If you don't need any licensed IBM software to run, you get a machine with only IFL. Rob
