For customers on Verizon Fios, particularly on the east coast, we have noticed that the connection speeds to our data center (located in California) do not approach the speeds that are achieved for connections that are more local to the area.
Sometimes due to network issues along the path from an ISP to Backblaze's servers, customers on these networks may not max out their connection speed to our datacenter. You may have heard of some similar performance issues on Verizon Fios connections with Netflix. The issue is very much the same. Unfortunately, there is nothing that we can currently do to resolve this issue, as it is one that lies with either Verizon or their peering partners.
Backblaze does not throttle your connection: The Backblaze client encapsulates data in 10MB chunks, uses https connections, uses a single connection at a time, so latency can play a very large role in overall backup speed.
If you've ensured you've set the Backblaze throttle is either set to Automatic or the slider is all the way to the right, indicating maximum, you've done everything on the Backblaze end that you can to improve your upload speed.
We have had some customers report improved upload speeds by using the Verizon Speed Optimizer: