I have two sites both with different clustermode (6210 and 8060) hardware but on the same domain. These FAS clusters house our company SHARE and HOME drives. Over the last 6 months SID resolution has been getting slower to now what I would consider painfully slow for some security groups. Via windows file explorer it sometimes takes 5 minutes to resolve the sids. Manually trying to resolve sometimes fails but if I wait a minute or two it will then resolve. We have increased the size of the cache dedicated to holding the SIDs 5x with no effect.