The mystery of speedtesters

BT Speed tester
Download speedachieved during the test was - 71.82 Mbps
For your connection, the acceptable range of speedsis 12 Mbps-76.45 Mbps .
Additional Information:
IP Profile for your line is - 76.45 Mbps

Upload speed achieved during the test was - 13.57Mbps
Additional Information:
Upstream Rate IP profile on your line is - 20 Mbps

TBB Speed tester
Typicall reports 59/8
Speedtest.net
Typically reports 59/14

Is the BT speedtester testing only the link between my modem and the exchange? The download is a lot higher than the other testers but reasonable for the profile. Seems like a big drop from 72Mb/s to 60Mb/s and something I should discuss with my ISP.

Edited by Andrue (Tue 29-May-12 19:15:48)

In reply to a post by Andrue:

Is the BT speedtester testing only the link between my modem and the exchange? The download is a lot higher than the other testers but reasonable for the profile. Seems like a big drop from 72Mb/s to 60Mb/s and something I should discuss with my ISP.

Good question. I guess only way to know is if it works for a Sky or TalkTalk FTTC user?

What does: http://mcslhr.visualware.com/myspeed/myspeed_line_ap... give?


And I feel it is important to look at teh Task Manager plots to see what is happening during each test - try all three or four consecutively and capture the screen for comparison.

In reply to a post by MHC:

What does: http://mcslhr.visualware.com/myspeed/myspeed_line_ap... give?

51 down, 17 up. CPU for the download had a brief initial peak but was mostly around 10%. I've had better off that test in the past, speeds closer to 60Mb/s in line with speedtest.net. Upload was 17Mb/s but CPU was bouncing between 80% and 100%.

Edit:Interestingly the detailed graph shows download speeds close to 80Mb/s for approximately as long as the CPU was maxed out (judging by eye - just under a second according to the graph). Upload graph has a couple of peaks but is fairly steady most of the time.

Download speed 50889 Kbps
Upload speed 17051 Kbps
D/load COS 83 %
U/load COS 98 %
Min RTT 2 ms
Max RTT 15 ms
Avg RTT 9 ms
RTT Consistency 13 %
Max Delay 21 ms
Avg Delay 1 ms
Effective Speed 66746 Kbps
Route Speed 262140 Kbps
Forced Idle 22 %
Route Conc 1.3


MSDL01: The download speed is too low for the latency/bandwidth of the connection

MSBW01: Bandwidth is much lower than speed attainable for the route being tested.

MSTR01: The data flow for this test is too erratic

MSMD01: TCP is waiting too long for data

MSTR02: The trip time for this connection is too erratic


Edit:This is my Win7x64 dual core laptop but it only has a 10/100 NIC.

Edited by Andrue (Tue 29-May-12 21:08:28)

Well I find that the BT speed tester (not the beta tester) always gives a lower result than any other tester with speedtest.net usually reporting the maximum my line is capable of.

WIth some AV and some lines one can see Speedtest.net report impossible speeds too

As line speeds go faster it is more likely that speed variations will appear wider. The price people pay for the 80 Meg service is no where near enough to buy 80 Mbps without contention.

Other way round for me now i am with Beastie.
Speedtest.net showing 24meg upload and quite regular. Previous ISP 37.45meg
BT non beta 41meg
Namesco 41.34meg
Visualware 40.6 meg

All within 3 mins of each other.

Have reported the problem today should easilly be getting 70 meg.

In reply to a post by MrSaffron:

WIth some AV and some lines one can see Speedtest.net report impossible speeds too

Yes, I've seen that, where people post 91Mb/s speedtest.net results on an 80/20 service and say "yippee!" but I think I've only had one silly result from speedtest.net in that respect and always discard them.