Q: Boost asio async vs blocking reads, udp speed/quality I have a quick and dirty proof of concept app that I wrote in C# that reads high data rate multicast UDP packets from the network.  For various reasons the full implementation will be written in C++ and I am considering using boost asio.  The C# version used a thread to receive the data using blocking reads.  I had some problems with dropped packets if the computer was heavily loaded (generally with processing those packets in another thread).  
What I would like to know is if the async read operations in boost (which use overlapped io in windows) will help ensure that I receive the packets and/or reduce the cpu time needed to receive the packets.  The single thread doing blocking reads is pretty straightforward, using the async reads seems like a step up in complexity, but I think it would be worth it if it provided higher performance or dropped fewer packets on a heavily loaded system.  Currently the data rate should be no higher than 60Mb/s.  

A: I've written some multicast handling code using boost::asio also.  I would say that overall, in my experience there is a lot of added complexity to doing things in asio that may not make it easy for other people you work with to understand the code you end up writing.
That said, presumably the argument in favour of moving to asio instead of using lots of different threads to do the work is that you would have to do less context switching.  This would clearly be true on a single-core box, but what about when you go multi-core?  Are you planning to offload the work you receive to threads or just have a single thread doing the processing work?  If you go for a single threaded approach you are going to end up in a situation where you could drop packets waiting for that thread to process the work.
In the end it's swings and roundabouts.  I'd say you want to get some fairly solid figures backing up your arguments for going down this route if you are going to do so, just because of all the added complexity it entails (a whole new paradigm for some people I'm sure).
