@bazzer wrote:
is PN doing something in the background when detecting above average usage?
No, what you are seeing is typical for a broadband connection that doesn't have any "QoS" (Quality of Service) enabled when the upload direction is being overwhelmed.
@bazzer wrote:
Why are my broadband speeds dropping so significantly when conducting these types of backup
The download speeds achieved, both under normal use and when performing speed tests, are regulated by handshaking sent from your computer (and router) back to the server you are interacting with on the internet. Essentially when you are doing a speed test, your computer (and/or router) will be sending through the upload path alternate messages to "send more data" or "stop sending while I process what I've got". Therefore if your upload path is being used anywhere near maximum capacity (as would be the case in uploading a massive backup), then those handshaking messages get delayed and the entire connection becomes exponentially dis-regulated, because those delays lead to message resends, and are multiplied by the increased latency.
Counter-intuitively, the solution is to put some sort of maximum speed limiter on your upload connection. While yes the peak upload speed will get reduced by say 10%, because the slowdown on an overloaded upload path is exponential, by running your broadband connection at around 90% of it's capacity, you can actually get a greater throughput with a lower bandwidth, and can massively improve latency for everything using the connection.
@bazzer wrote:
I began to wonder why it was taking so long and carried out random speed tests.
Try running the DSLReports speedtest and clicking on the green [DSL] button.
If your router is managing your upload path adequately, then you should see a resulting "BufferBloat" score of "A" or "A+", otherwise you have a starting point for solving your problem.
If your router does have a QoS setting or a upload rate limiter, then start by trying limiting the maximum upload rate to about 90% of your usual upload speedtest result (so 90% * 18.24Mb = 16.4Mb), and repeat the above test to see the improvement, and repeat as necessary changing the percentage (up or down) to achieve maximum throughput and minimum latency.
If your router doesn't have these controls, then does the software on your computer that performs the backup to the internet, have any sort of rate limiting ? If so try setting that limit to say 80% of your upload speed (so 80% * 18.24Mb = 14.6Mb).
At least doing that means that you won't be saturating the upload connection, which means while a backup is in progress that your internet will be otherwise usable, and although you have artificially limited the backup speed by 20% the actual throughput loss will probably be less than 10%.
