Hi,
"...experiencing system freeze as the WIreportserver.exe consuming 100% cpu..."
1. Do you know which webi report(s) that are trigger the WIREportServer to CPU spike? If not, I'd suggest you to enable the Webi tracing to identify the troubled Webi report and its work flow.
2. After the troubled Webi report and its work flow is identified, do you experience the same CPU spike if this report is open and refresh in a Webi rich client?
At last, there is a webi related CPU spiking issue fixed on "ADAPT01713425 Description: When opening webi report in attachment the webiprocessingserver is taken 100 % of CPU forever.
New Behaviour: the issue is fixed" on BI4.1 SP02 Patch2.
Hope this helps,
Jin-Chong