We’re switching from Broker Server to UM 9.6 for pub-sub. Keeping all parameters same, we see the IS response times gets drastically increased when the switch is made in the Messaging Alias from Broker Server to UM. Going back to Broker Server from UM improves the IS 9.6 performance by 5 times.

Although lot was said about Low Latency of UM, we’re seeing quite the opposite. We ran several performance tests with different UM/IS and the results were consistent. UM is at least 5 times slower than Broker Server!!

A case has been opened for Software AG R&D/Support but wondering if any one has seen this problem and has fixed it.

wM 9.6 still does not have complete support for native Pub-Sub. Would recommend to check the supported features before switching to UM.
Also there are no Technical Reports published by SAG for UM (Native Pub Sub). We have reports for UM (JMS Pub Sub).
If you use JMS Pub-Sub, as per the SAG reports, UM seems to perform better, especially at higher transitional volumes and message size