I've found and fixed a big problem with the http audio streaming at Magnatune. Several people in Europe had complained about being unable to reliably stream our music.
My own tests found transfer rates of 50k/second from he3.magnatune.com but 3mb/second from www.magnatune.com. Since I know Apache (which is on the www server) is slower than mathopd (which is on the he3 server), either there was a software bug in mathopd or a machine/networking problem.
The problem was that the 100mbit Intel Ethernet card was set to autosense its speed, and wasn't doing that correctly, so we were getting 1/60th the speed we were supposed to get. This new problem appeared few months ago when I moved from http://he4 to http://he3 -- he4 didn't have this problem (he3 had more disk space, which we needed). For the Linux geeks out there, the solution was adding "options e1000 Duplex=2,2 Speed=100,100" to the /etc/modprobe.conf file and rebooting. This is spelled out by Intel docs at http://support.intel.com/support/network/sb/CS-009209.htm#speed_duplex
I'm now getting 5.5M/second transfer rate from http://he3, which is the machine that feeds all our audio streams, and this seems like a more sane speed (I believe that's 44mbits, on a 100mbit line).
Magnatune fans: please let me know if you see an improvement in either drop-outs or time-to-start-playing-the-song.
On a separate topic, I thought the problem might be the "mathopd" web server I'm using, and investigated and benchmarked several high performance alternatives. I finished by using thttpd http://www.acme.com/software/thttpd/thttpd.html because the comparison charts http://www.acme.com/software/thttpd/benchmarks.html they created show mathopd a close running up to them (in comparison, Apache is 1/5th as fast with large files) which agrees well with my own tests 2 years ago, where I found mathopd to be the fastest.
My own use of the "ab" benchmark tool finds thttpd to be about 25% faster than mathopd with a moderate load (10 users) and a mp3-sized file (3megs).
To run my benchmark, thttp took 14 seconds, mathopd took 19 seconds, and apache took 78 seconds. This is why a specialized web server is a useful thing when serving lots of multi-megabyte files.