BT Speedtest needs an overhaul - wide discrepancy to others

[#1]

This morning I ran a BT speed test at 08:15  (approx) which gave me a download speed of 931 kb on a synch speed of 2016 (which has been stable for 2 days)
I run at least 2 BT speed tests per day, as my SNR figure is running quite low (at present 4.8 )  I am also running routerstats, and monitor the graph for Download SNR, which gives me an almost straight line all day long, no vicious spikes, just background noise ripple of .1 db or so.... MY line is rated at 2 megs so I don`t expect to see big numbers in the speed department, generally it runs quite happily all day long at about 1.2 to 1.3 megs... it is a very stable line, with little noise....
so why is BT speed tester giving such dire speed figures?
BT speed test 931
My Broadband  1380
Speedtest.net 1380
Speed.io   1383
all done immediately after the BT speed test....

[#2]

Update on my previous posting
10:28  Current synch speed from router stats 2016    SNR figure 4.8  download attenuation 63.5
BT Speed test      1301                     Your configured download throughput speed for this service is 1500 k
My Broadband 1380
Speedtest.net  1380
speed.io           1378

[#3]

Presumably you've no other applications open when running these tests? A simple send/receive from a mail client could easily skew the results if it happens at the same time you're running one of the tests. I'm presuming that you're also using the latest version of Java, and do you encounter the same problem across multiple web browsers?
The second set of figures you've posted look fine to me although admittedly the figures from your first post are a little low.
Is this actually causing you problems? We've not received any system outage notifications from Wholesale and I've not seen any similar reports elsewhere (although I haven't spent a great deal of time in the forums over recent days).
A speed test I've just run on my circuit isn't really indicative of any issues:
[quote author="BT Speedtest"] Download speedachieved during the test was - 5258 Kbps
For your connection, the acceptable range of speeds is 1200-7150 Kbps.
Additional Information:
Your DSL Connection Rate :7104 Kbps(DOWN-STREAM), 832 Kbps(UP-STREAM)
IP Profile for your line is - 6000 Kbps
Compared to the others:
mybroadbandspeed.co.uk - 5448 Kbps
speedtest.net - 5460 Kbps
speed.io - 4738 Kbps

[#4]

Hi Bob,
No, it isn`t causing me any problems, apart from "curiosity", as to why the BT speedtester is ALWAYS slower than the other major players.... Seems as if BT have conciously throttled their speed test equipment, to enable them to provide less service to the broadband customer base, (including all isp`s)...
As I have shown in many previous tests, all the other major players in the speed tests sites, seem to run very close on results....
No I do not run any other stuff whilst I am doing the speed tests... and all software is up to date...