New ASUS DSL-AC55U slower than Plusnet TG582n

[#1]

I recently bought an ASUS DSL-AC55U router in an attempt to sort out a slower-than-normal ADSL2 broadband connection. At first, there seemed to be an improvement, but a detailed comparison of the ASUS and Plusnet routers suggests that the ASUS is actually slower by around 2Mb/s on downloads. I have been careful to configure the ASUS to exactly match the settings specified by Plusnet. Can anybody suggest a possible reason for this performance discrepancy?

During testing, I also tried plugging in both routers (via a filter of course) to the external socket and the internal test socket behind the face-plate of the OpenReach master socket. Speed was higher using the internal test socket with both routers, again by about 2Mb/s. What might be going on there?

Many thanks.

[#2]

Regarding the performance difference between the DSL-AC55U and the 582n, it's rather stating the obvious, but the reason is that they're different devices.

The better speed in the test socket indicates that your extension wiring, which gets disconnected when you expose the test socket, is a problem. Either disconnect the extension wiring if you don't use the extension sockets, or get a filtered faceplate.

[#3]

Thanks for the reply, but I was rather hoping for some deeper insight than simply "they're different devices". The TG852N is a no-frills low-cost device and not particularly up to date. Is it unreasonable to expect a better performance from the AC55U?

[#4]

In the absence of any DSL line stats, such as line speed, attenuation and noise margin, the 2mb difference may be down to differing modem circuitry within the routers.  The TG582n is broadcom based.  The DSL-AC55u is currently unknown as it looks like a relatively new model.

[#5]

It's yet another Asus DSL model using a MediaTek (TrendChip) modem chip. These things have had all sorts of problems, and perhaps have a reputation for being faster but less stable. Unfortunately, newer and more expensive does not necessarily make it better at ADSL.

[#6]

Many thanks for the additional insight. Looks like I've been had. Perhaps a future firmware upgrade will correct some of the poor performance.