Since moving to Zen's G.fast service, I get the full 330/50 sync at about 200m. But one thing that is clear is that single-thread speeds, while not appalling, are pretty poor compared to multi thread.
Just to give some figures, speedtesters are giving 220-280 Mbps and multi-thread downloads seem to be hitting that 300 Mbps mark. However, single-thread downloads are a bit enemic since speedtesters say usually under 100 Mbps and just trying HTTP downloads from different sources seldom reach max speed, and it's not unusual for them to hover around 120-220 Mbps. If they do reach max speed, it can take a while - slow ramp up.
I could be experiencing a situation where the servers I am downloading from do not have sufficent capacity, but given that the fact that speedtests also highlight the same thing I am thinking it is not the issue. Perhaps the slow ramp up may be caused by web server configuration to deal with the load.
I've gone through basically all what Zen have asked me to do, and then some. Stuff like using their supplied router with the Openreach modem. I've done more, such as trying two different modems, three routers, multiple wired and wireless devices, different browsers, getting results no different.
They have recently sent an engineer out who technically did not find a fault at all (which is what I was expecting) but Zen did not want to change backhaul until this had been done. There was a minor balance issue which did not quite meet the fault threshold, but since having that fixed the downstream attainable rate is looking a bit happier.
Before:
xdslctl info --stats
xdslctl: ADSL driver and PHY status
Status: Showtime
Last Retrain Reason: 0
Last initialization procedure status: 0
Max: Upstream rate = 61552 Kbps, Downstream rate = 338781 Kbps
Bearer: 0, Upstream rate = 50005 Kbps, Downstream rate = 330011 Kbps
Link Power State: L0
Mode: G.fast Annex A
TPS-TC: PTM Mode(0x0)
Trellis: U:ON /D:ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 3.6 7.5
Attn(dB): 31.0 0.0
Pwr(dBm): 0.0 3.9
After:
xdslctl info --stats
xdslctl: ADSL driver and PHY status
Status: Showtime
Last Retrain Reason: 200000
Last initialization procedure status: 0
Max: Upstream rate = 61789 Kbps, Downstream rate = 344897 Kbps
Bearer: 0, Upstream rate = 50005 Kbps, Downstream rate = 330011 Kbps
Link Power State: L0
Mode: G.fast Annex A
TPS-TC: PTM Mode(0x0)
Trellis: U:ON /D:ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 4.1 7.6
Attn(dB): 31.0 0.0
Pwr(dBm): 0.0 4.0
Either way, here is one of the TBB speedtests:
Perhaps even if you are not on G.fast but are on Zen with one of their "Fibre" products, you could share you experience of single-thread performance. Would be much appreciated, especially if you were able to resolve the issue if you had one since it is something I wish to do.
I would also like a second opinion on the provided TBB speedtest since I believe it to be indicative of some problem in their network - what do you think? I was under the impression such single-thread performance could mean there is an issue with backhaul.