[Info-vax] VUPS.COM relevance for modern CPUs

[Volker Halle]

Mark,

I've been using this procedure in the past (and fixed some problems with faster Alpha CPUs), to obtain CPU speed estimates during migration projects to the Stromasys CHARON emulators. In the beginning, those emulators did not perform - CPU-wise - well enough for emulating the faster Alphas (1 GHz or above). Never was a problem for VAX.

To get an estimate of the CPU speed of the customer's system, which should be migrated, getting a plain DCL procedure being executed was the easiest way to get an idea of the CPU performance. Yes, I know, system performance is more than CPU performance, but CPU speed of the early emulators was an expected bottleneck.

Itanium was never a target for running this procedure, as there was/is no Itanium emulator.

The procedure tries to execute a close DCL loop to prevent IOs as much as possible, they would disturbe the CPU speed estimate. This is why you just see Supervisor mode (or higher) and no user mode, as that would require an executable image.

There are certainly better and more exact CPU performance measurement tools, but a DCL procedure was the easiest thing to transfer to the customer's system and be run to provide a CPU speed estimate.

Volker.