Joined: 06 Jun 2008 Posts: 8214 Location: Dubuque, Iowa, USA
I just try if it's possible to use 64-bit addressable real memory capability to find better performance.
First, unless you have a KNOWN performance issue (such as batch jobs not completing in the batch window), it is rarely a good use of resources to attempt to improve performance. I haven't a Z9 to test with, but I suspect COBOL is probably close to 100 million lines of code executed per second of CPU time -- so performance concerns need to be reviewed with this in mind.
Second, merely changing from 31-bit to 64-bit addressing will NOT have any impact on performance -- if program performance is a dog with 31 bit addresses, it won't suddenly starting running faster just because you increased the available memory.
Third, programs can be CPU-bound or IO-bound (meaning the program is waiting for CPU or IO). An IO-bound program will not be helped by anything CPU-related (including memory) unless the issue is a lack of buffers in which case adding buffers will improve performance (but adding buffers will not require 64-bit addressing, either).