I recently learned about this site: http://testmy.net/
I'm not to sure about their results. The test gave me 19.9 Mbps down and 3.8 Mbps up...which sounds ok...except for one minor detail. I'm on a 40 Mbps symmetrical fiber connection.
SpeedTest.net gives me 30.04Mbps down and 33.08Mbps up which is a bit more believable, as it's 6pm on a Friday and the (nonbusiness/best effort) bandwidth isn't guaranteed.
Yeah, I often get similar results. I just changed ISPs. My old ISP package was 5Mb down and 0.5Mb up, with SpeedTest.net often telling me I was actually getting slightly higher speeds (e.g., 5.2Mb down/0.52 up) than that, which made me pretty happy to be getting more than I was paying for. When I got my new ISP, they told me to test out my new, faster speeds using testmy.net. The new speeds I'm paying for are 20Mb down and 1Mb up. But testmy.net frequently tells me I'm getting between 8-13Mb down and about 0.65Mb up. Or in other words, about 50-65% of what I'm paying for.. Yet SpeedTest.net says 19Mb down and 0.8Mb up.
Funny that the new ISP would tell me to use a service that consistently gives lower values when bragging about how much faster their speeds are compared to (what was) my current ISP. . .
Somehow I felt happier about my old ISP's philosophy of "under-promise and over-deliver" compared to my new ISP's philosophy of "over-promise and under-deliver."