user14316: -maxsigcachesize= Limit sum of signature cache and script execution cache sizes to 
What is this?
What is a sigcache?
What happens if it is set low and Can it have a bad effect?

user208: Bitcoin Core caches the outcome of script and signature validations, so that when they are reoccur, they don't need to be repeated.
A common case for this reoccurrence is the fact that typical transactions get processed twice: once when received as an unconfirmed transaction individually, and once when it is mined in a block and that block is processed. The script validation cache avoids the need to run the script again a second time, if it happens within a sufficiently short period of time.
You can safely ignore this option; its default value should be more than adequate.

14316: <p>-maxsigcachesize= Limit sum of signature cache and script execution cache sizes to </p>
<p>What is this?
What is a sigcache?
What happens if it is set low and Can it have a bad effect?</p>
 208: <p>Bitcoin Core caches the outcome of script and signature validations, so that when they are reoccur, they don't need to be repeated.</p>
<p>A common case for this reoccurrence is the fact that typical transactions get processed twice: once when received as an unconfirmed transaction individually, and once when it is mined in a block and that block is processed. The script validation cache avoids the need to run the script again a second time, if it happens within a sufficiently short period of time.</p>
<p>You can safely ignore this option; its default value should be more than adequate.</p>
