Hello, We're working on a server which will provide service to a large number of mostly idle, low-bandwidth clients. we've use boost::asio as the basis for this, and so far it's working very well. We recently added SSL support, which was very straightforward and seamless. We're starting to look at the scalability of our SSL server, and are seeing some bottlenecks with memory usage. We're seeing about 50KB allocated for each SSL session, even when they are idle. That limits us to somewhat less than 40K users on our box with 2GB of RAM. Our non-SSL version takes about 10KB per user, and we can handle somewhat less than 200K users. Of this 50KB, it looks like 16KB of this is for the OpenSSL BIO object, possibly a bit more with OpenSSL's internal buffers. There is another 16KB buffer stored in the "impl" field of openssl_stream_service. The server is always waiting for data from the clients with an async_read_until, and that also creates a 16KB buffer in its openssl_operation buffer. That gets us up to 48KB of storage for the buffers of each idle connection. So, a few questions. First, does this seem about right? Am I reading the code correctly? Second, it looks like it's harmless to just make these buffers smaller, maybe 1KB, including the BIO buffer. Does that seem reasonable? Can anybody think of a problem with that approach I'm overlooking? I'm certainly no OpenSSL expert, so it's fairly likely... Third, is there a better way to do this? Most of boost::asio uses memory very efficiently, and I wonder if I'm doing something wrong to cause it to allocate all of this memory? Thanks for any thoughts or help! ----Scott.