I've had "Gigablast" (940Mbps/35Mbps), Internet service for months and rarely get above 600Mbps down and 5-6Mbps Upload. I've replaced cables, updated LAN drivers, factory reset my modem and router, even got a Cox modem. No change in speeds.
Connection: Wall outlet > RG59 > Netgear CM1000 modem > Cat6 > TP-Link X3000 Router > Cat6 > Windows desktop.
Technician came out last Saturday and hooked his gadget to the post at the end of my driveway and said it wasn't provisioned correctly. Said he did that, showed my his gadget which showed 940/35 speed. Tested, got about 800/32. Hooray! Then 2 days later back to the same speeds before. Last night my speed was about 280/.88!!!! So the same tech comes out today. Disconnected the cable from the post, tests, reconnects, asks me to try again. 598/33! Much better. He leaves. 10 hours later, back to 548/10. Sigh. I don't know what to do.
*All tests are done from Cox speed test, Google's speed test, and the speed test built into my routers UI. No other devices, wired or wireless, were connected to network at time of test.