Appropriate Workloads
Mainframe characteristics are designed for such business workloads as transaction processing or large database management. Mainframe design emphasizes input/output performance, implemented via channel I/O. Historically, the principle is to offload I/O activities from the CPU as much as possible, and the z/Architecture additionally offloads cryptographic calculations. Mainframes can scale to numerous processors in a single frame, e.g. up to 64 processors in the case of the System z10 EC Model E64, which gives as much as 28.000 MIPS.
On the other hand, mainframes in general, and Linux on System z in particular, do not perform well for single task computations. Examples include most scientific simulations, weather forecasting, and molecular modeling. Supercomputers, including Linux-based supercomputers, excel at these workloads. This distinction has blurred since the introduction of the System z10, a machine based on quad-core 4.4 GHz processors with hardware decimal floating point. In this regard, the System z10 more resembles a supercomputer processor than previous mainframes.
Mainframes do not provide graphics or sound adapters, and are as such ill-suited for digital media editing or computer-aided design (CAD) except perhaps in support roles (e.g. content storage, parts inventories, etc.)
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