Varying broadband speeds

Can anyone help explain this situation. I currently have Tiscali/TalkTalk and my ADSL runs at about 1.3Meg.

On the line checkers for TalkTalk Pro and Orange Broadband it says I can get 6.3Mbps and 7.0Mbps respectively.

The BT ADSL checker says it is very unlikely I will receive broadband, Plusnet estimates 0.5Mbps, whilst Be estimates at 0mbps!

Currently using a very unreliable standard issue Tiscali Siemens SE587 which shows the attenuation as 63.5db and SNR as 12db.

Can anyone estimate what speed I could get and why Orange and TalkTalk's estimate is so much higher?

Thanks in advance,

Nathan

Bad news I'm afraid - with that attenuation you will struggle to get any decent speed as it is the highest the router can report so may well be even higher.

All the ISP estimates should come from the BT database (which can be wildly inaccurate) so I've no idea why those two differ from BT and Be which appear to be a lot closer to the dismal truth.

LLU providers take line length data from Openreach

BT Wholesale customers take BT wholesale data which can have feedback based on actual line performance from you or others in the area.

Hence differences are potentially great, then maybe add some marketing sping and viola even widely varying figures when the same database was the source