Take a "truly accurate speed test" at testmy.net.
From the site: TestMy.net is the first and only fully HTML5 & PHP driven speed test online. Unlike other connection speed tests that require third party applications like Flash or Java, TMN uses only your web browser. This makes TestMy's speed test more sensitive to browser misconfiguration and is an excellent way to highlight performance differences between browsers. Users of TMN can see all browsers are not created equally.
Why Should I Test My Speed?
Simple, to make sure you're getting what you pay for. This speed test is useful if you feel a connection slow down or want to see how your Internet is performing. This isn't like any other broadband speed test. TestMy's proprietary method is proven to help identify issues other speed tests fail to detect. The TMN Speed Test shows your true speed.
testmy.net