In the BCAAA.ini file (by default installed under C:\Program File\/Blue Coat Systems\BCAAA) there is a 'NumThreads' parameter which controls the number of threads BCAAA will create upon startup per realm.
 
BCAAA.ini file:
..
..
; Set number of threads to use; recommended value is 2; if set to 0,
; only a single thread is used.
NumThreads=2
..
..
 
This value can be increased up to 100 however, please be aware this could negatively impact performance, therefore it is recommended is to keep the NumThreads=2 for standard installations.

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Additionally if the realm in question is an IWA realm, then increasing NumThreads will probably make no difference as Windows limits the number of outstanding authentication requests to 2. Therefore, increasing NumThreads will not increase the throughput of an IWA realm.
 
Also, increasing the “NumThreads” value is not going to make any difference in a Kerberos deployment.  This setting is normally altered to help reduce the NTLM (netlogon) bottleneck.