http://sf.net/projects/iocpsock Super fast sockets for windows NT/2K/XP, no joke. docs (not done yet): [http://sourceforge.net/docman/display_doc.php?docid=23086&group_id=73356] [http://iocpsock.sourceforge.net/netio.jpg] Pardon the "noise" in the display. sqlserver running on "rufus" must have been serving-out during the test run. For each time I raised the -sendcap on the sender, I checked -recvburst on the receiver (rufus). Notice how the -sendcap is acting as a throttle in the graph. Notice how burst detection is kicking in and raising the WSARecv pool to compensate. This "burst mode" thing is nice, but I find "flow-controlled" to be the better way for a web server. A -sendcap value of 2 should be sufficient. A -backlog setting of 200 I found to be extremely "bullet-proof" for the front-end. BTW, the sender console is missing this in the display: proc mash s { puts -nonewline $s [string repeat Q 4096] } It seems to be as efficient as I can get it. There is one item to note. As it doesn't have any polling behavior at all, events will not be repeated. IOW, if your fileevent readable handler decides not to service a notice to read (doesn't call [read] or [gets]) and no bytes follow, it will not be repeated as is the behavior of the core socket driver. tclhttpd doesn't have this issue, but some code might.. Especially the ones that check for EOF before the [read], which is backwards. Other things to note.. now does blocking mode and has an async style close that "lets the instance go" and does a background destroy when the last reference returns. That async close helped concurrency considerably. ---- [Category Package]