I actually made my own modification of Robin Walker's speedtest - All it really does is increase the payload by 8x from 128K to 1024K. Gives much more consistent results for faster connections. (Oops... I forgot to change the "128K" text to "1024K" when I uploaded...)
http://homepage.ntlworld.com/xuepei/st.html
Actually I find the ADSLGuide speed test extremely innaccurate - Just tried it with the following results :
First run :
Downstream
around 50000 Kbps
Upstream
around 80 Kbps
(MaxSpeed crashed my browser so I havnt got the actual values)
Second run :
Downstream
22850 Kbps (2,856.3 KB/sec)
24678 Kbps (inc. overheads)
Upstream
34 Kbps (4.3 KB/sec)
36 Kbps (inc. overheads)
Somehow I don't think the 5MB upload I just did to a US server in 4 seconds went at 34Kbps... or 80Kbps for that matter...
And the MaxSpeed test?
First run : Downstream 5mbps Upstream 8mbps
Second run : applet froze
Third run : crashed my browser (and took all 8 other windows along with it, including the one in which i was typing this post, so I had to start again)
Hmm... I think I'll stick to Robin Walker's test, for "normal" connections and my mod for "fat pipe" connections...