I'm on a Virgin Media cable connection which has a claimed speed of up to 150 Mbps. The ThinkBroadband Speed Test says the download speed is only 77 Mbps (peak 87 Mbps), but SpeedTest.net rates the download speed at 141 Mbps (peak 147 Mbps). Which one is correct and why should the two be different?
They are both probably correct
The difference is likely that Speedtest.net only offers a multithreaded test. This helps saturate connections and hides network contention issues (something VM is infamous for unfortunately). The TBB test uses both single and multi-threaded tests (depending I think on whether you are logged in or not). If you haven't done so yet ensure you are logged on next time you run the TBB test. It will then run both single and multi threaded tests and you'll probably see the single threaded test being lower than the multi.
Sadly that's just the way VM run things. It's generally accepted that while BT based products don't offer the headline grabbing speeds they do tend to run at the same speed 24/7 and offer a smooth and reliable experience. VM connections offer higher speeds outside of peak periods but on-peak often slow down a lot and suffer from jitter - the latter making them the bane of online gamers.
Edited by Andrue (Fri 21-Aug-15 22:56:32)