The BT checker seems to be consistently conservative by a small but decent chunk (15%? 20%?)

Makes sense - if the user gets less than they expected, then BT will get complaints. It's only an estimate after all, so perhaps they went for something like 2 standard deviations below the mean for any particular distance.

Edited by arfster (Fri 13-Apr-12 10:08:11)

Predicted was 76.6/20

Actual is 75/17.5

sync is 79999/20000

Noise margin is 16.8db

IP Profile for your line is - 77.43 Mbps

Edited by Alnath (Fri 13-Apr-12 10:41:05)

Predicted 69.5 / 20

Actual 75.05 / 15.34
iechyd da

profiles 77.43 / 20

Edited by paul1360 (Fri 13-Apr-12 10:53:40)

In reply to a post by arfster:

The BT checker seems to be consistently conservative by a small but decent chunk (15%? 20%?)

Makes sense - if the user gets less than they expected, then BT will get complaints. It's only an estimate after all, so perhaps they went for something like 2 standard deviations below the mean for any particular distance.

I'm sure I read somewhere that the the estimated speeds took the effects of crosstalk into account which will be an issue as more people get connected.

(profile before upgrade was 34.5 / 6.5)

Predicted 26.5 / 5.5

Actual 37.5 / 8.5


profiles 38.0 / 10.0

800 to 900 meters to cab

Holds breath for vectoring in 2 years time !

Predicted 34.6 / 5.9

Actual 55.8 / 17.4

Approx 600m from cabinet.

Predicted 60 / 20

Speedtest.net reports 76 / 17
http://speedtest.net/result/1891249896.png

My sync from the modem is 79999 / 20000 and I am around 300m - 340m from the cab.

Downloaded a game from steam last night and it was downloading at 9.1MB/s.

Happy days.

In reply to a post by arfster:

The BT checker seems to be consistently conservative by a small but decent chunk (15%? 20%?)

Makes sense - if the user gets less than they expected, then BT will get complaints. It's only an estimate after all, so perhaps they went for something like 2 standard deviations below the mean for any particular distance.

If I remember correctly from approximately 50 years ago, 2 standard deviations below the mean would take you down to about 2.5% of the mean. Not 80-85%.

Predicted was: 61/20. Actual sync is 79999/20000 (Hacked OR modem). However speeds are 37-49 down and 15/16 up. Max download from usenet is 4.8MB/sec, which tends to bear out the 37Mbps result.

In reply to a post by roboraver:

(profile before upgrade was 34.5 / 6.5)

Predicted 26.5 / 5.5

Actual 37.5 / 8.5


profiles 38.0 / 10.0

800 to 900 meters to cab

Holds breath for vectoring in 2 years time !

I don't want to rain on your parade but I wouldn't hold your breath; vectoring will only help if crosstalk is reducing your speed from the best that can be expected for your line length. It looks as though you're already doing pretty well at 800-900m. Profile 30a, if/when it comes, might give you an extra Mb or so, but I wouldn't hold-out much hope.

However, if your cabinet becomes busier, crosstalk might reduce your speed from its current level, and then vectoring could restore it.