IIRC the HTTP 1.1 spec restricts clients to a maximum of 2 connections per server (I think it's 4 for HTTP 1.0, as that one didn't have keep-alive connections). So remember that if you do force it to make more than 2 connections (which you can do in IE too with a little registry magic), you're breaking the spec and there are servers and admins out there that won't thank you for doing so. Plus on low-bandwidth connections (dialup, ISDN, lo-spec DSL), the extra overhead from more connections will eat into whatever small performance increase you might have got. They did some tests and it turned out more efficient to reuse the same connection than to make multiple simultaneous ones, assuming ideal network conditions. YMMV of course.