The BBC iPlayer speed checker was a useful tool for those chasing to see how their connection might perform for video streaming, but alas the tool appears to have been retired and looks set to be replaced by a table showing what speeds different types of iPlayer content will require.
Of course other speed test tools exist, but the majority are designed to show the highest possible number so that people are happy, our flash based speed check is possibly the only one that conducts a single thread download test (tbbx1) and a multiple thread test (httpx6). The single thread test should show how contention or congestion is impacting on a broadband connection and is closer to what you would expect for a video stream rather than when using multiple downloads at the same time. On a good connection the two download tests should be near identical, but when issues like congestion, bad RWIN/MTU values are affecting speeds you will see the two results diverge.
Of course not everyone can run flash and to that end we have another speed test that does not need flash or java and thus will run on the majority of tablets and phones as well as computers. The tester is marked as beta because we are still adding various enhancements, with this weeks change being that we are detecting the hardware you are using automatically. The web based test does not perform a single thread test currently.