In large organization or in organization that perform a lot of Internet request per second, sometimes, when you have the Proxy configured as man-in-the-middle to intercept HTTPS certificates, this operation can create a high load on the server due high I/O requests necessary to perform the interception.
This can cause a degration of the performance of the proxy and consecutively a low Internet speed.
To minimize the impact of SSL interception operations, is recommended to reduce the number of certificates to intercept, disable the SSL cache and also, if you use ACL, disable the SSL Bump for the Error Page.