FairCom DB Server takes advantage of any processors available to it. The performance depends on the saturation point with your specific application. Specifically, performance depends on whether your application is bound by CPU, memory, or disk I/O.
We have seen situations where simultaneous multithreading (SMT) with two threads on a single CPU core provides close to the same performance as two CPU cores, and we have seen situations where it does not. The only way to definitively understand your performance is to run your application in both configurations and monitor the system throughput.
The FairCom DB statistics monitoring program, ctstat, provides a good way to monitor your application’s throughput. You will need to run your application for a period of time in both manners to see which yields the best throughput. Documentation for ctstat can be found in the FairCom DB Server Administrator's Guide.
To use this utility, use the ‑text option as it dumps everything FairCom DB monitors except for the function timings. Note you can enable function timings using the ctstat ‑wrktime on support, but this will impact performance as the function timings are a costly exercise. The rest of the monitoring does not impact performance because the Server is already keeping these metrics.
The output from ctstat ‑text will go to a text file called snapshot.fcs. With SMT enabled, run this utility 5 or 6 times every 10 minutes over the course of an hour (or longer as you feel appropriate). Move the snapshot.fcs file from your first run to a new location. Then repeat the same exercise with the application running the same tests with SMT disabled.
Now that you have two snapshot.fcs files, you can view them with an editor and compare selected metrics. The ctsnpr.exe utility allows you to read a snapshot.fcs and dump it to a comma-delimited file you can open in Excel. The usage for ctsnpr is:
ctsnpr.exe snapshot.fcs > snapshot1.out
Be sure to update snapshot file parsing utility, ctsnpr, to a version that supports the correct SNAPSHOT.FCS file format.
Repeat this for both snapshot.fcs files and open them in Excel to compare the results.