Accurate Connection Speed.

Hey, I'm just wondering how do I measure my my connection speed. I pay lot s of monthly bill for my internet and got the fast connection from SBC Yahoo for gaming. Sometimes my connection goes 2.5Mb/s and somedays goes to 2 Mb/s but I wonder how could I test my connection speed accurately. I got a feeling I'm being rip off here and not getting enough speed for what I pay. I got good modem and a gaming router so it shouldn't be the choke point, on my pc I using ethernet 1Gbps interface. Now with test like 2Wires.com or CNET it says that my connection speed is 2.0Mbp/s when I should be getting 2.5Mb/s.

2.5 is the theoretical max you can download. The only time you will get that speed is between you and the isp. Outside of that it will be lower. If your getting 2.0 from all the testing sites then your ok.
Might ask your isp if they have a speed test you can connect to on their servers.

both dsl and cable modems have a small amount of overhead. dsl is a little bit more (around 5-15% usually) and cablemodem is around 5-10%.

If your connection is stated at 2.5MB and your getting 2.4MB then that is most excellent