Sizing New C8 Box - Will Multicore Make Big Difference?

[kazanec]

We're preparing to migrate from S7.3 to C8 and I've been asked to size a new server. Will I see more of an increase in performance moving from dual dual-core processors to dual quads? I suspect 4GB of RAM should be enough.

Thanks!

[praveennb]

Yes multicore does make a difference. by allowing multiple bibus process to be run simulataniously, so that more reports can be processed.

4GB Ram Depends on the amount of reports being generated at any given time, you can setup the server to use 3 Bibus processes
(Maximum number processes for the Interactive report service setting) for reporting service and 1 for batch report service. assuming each bibus process consumes arround 1 GB RAM.

I have done extensive testing for Cognos 8 reports with many fields like example  reports contains 60 odd fields!, with some fields being rendered conditionally  this type of reports consumes huge amount of memory. almost maxed out the Ram usage for each process it was like 1GB+ and in some cases where the report had multiple sections with 60 odd fields the bibus process crashed out, we had to split the reports into different sections to get this working

if you were to run 4 such reports at the same time then the server memory will be maxed out.

If your reports typically consists of fewer fields and less complex calcuations you can try to increase the number of processes

search for  cognos 8 performance tuning cheat sheet and cognos 8 performance tuning settings in cognos support
this documents will help u to size the server properly.

on a side note moving to C8 has increased the overall perfomance of report execution time. also Windows 2003 Std edition only supports upto 4GB ram.

good luck with your migration.