SEPM 12.1.4023 Performance

We've had a couple of issues with SEPM 12.1.4023 performance issues - or what appear to be performance issues.

1. The SEPM native web site ceases to work and only a system reboot seems to resolve this
2. Notifications pertaining to virus outbreaks and remediations are sent out days later, often 3+ days after the malware was contained and the infected file deleted

SEPM in our enterprise is running on VMware guest, Server 2012 R2 Datacenter, 8GM RAM.

Any ideas / thoughts are much appreciated...

-SEPM User