Best practice would say that you should remove signatures which are not important - which should decrease inspection load a bit.
However you need to think of one thing before doing this:
Am I only interested in attacks againt my infrastructure? (Victims in my network)
Am I interested to check for attack related to my infrastructure? (sourse or victims in my network)
Apart from the obvious question - what happens if you do install HP open view - will you remember you turned off this signture?
That being said, I understand you already went past the stage where you monitored your traffic in promiscous mode for several weeks and are confident what you actually have in your network - you identified signatures firing false positives and trimmed them. If so, you can also disable some default signatures not related to your infrastructure.
Will you see a superior gain of performance - I doubt so. But it's a good place to start.
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...