Cache invalidation is affected by the number of AQ threads allocated to the Sponger. It also affects the number of concurrent tasked handled by a Sponger instance.
There is a AsyncQueue? = 1/0
in the SPARQL section of the virtuoso ini file.
This is obsolete.
Infact the AQ only is used to protect cache from bad data
Steps:
# virtuoso.ini ... [SPARQL] ... AsyncQueue = 1 ...