There are many reasons why you may see higher results with your ISPs speed test, in this case Verizon's. Some of which you touched on.
First, it's within Verizon's network so you're not really being routed out to the Internet. TestMy.net is outside of all ISP networks, hosted in the same data centers as millions of other websites. My servers and the networks that connect them to the Internet are >. Purpose built for the task, very over powered. The main server is only running at 10% capacity, even under high stress it rarely goes above 15%. I replace servers before they regularly run at 20%... my point is that I keep plenty of resources on tap.
When testing at TestMy.net it's more likely than not that you'll have a dedicated core for the duration of your test. No matter how many people are testing resources don't collide.
Location can be a factor but the technology behind the test first must be sound. And... the other one you're using isn't. It's a well known fact that ookla speed tests don't return all the information. Portions of the result are clipped right out, they say that it's to offset high CPU and blah blah blah during the test. Whatever the reason, the algorithm usually makes results look better... TestMy.net calls it how it is, making no adjustments.
Sometimes something as simple as TCP tuning can make all the difference. Looks like you're on Windows 7, TCP Optimizer is a free and easy tool for adjusting that in Windows. MTU or rwin may be set wrong and that would slow you down. When that happens it often doesn't show on other speed tests but trust me it affects your browsing and transfer speed.
Before you get into that let's run some different tests. Take your average speed in Mbps and double it, we'll just say 25. So for the next tests we'll manually select 25 MB from the download test. Manual selection will give a better comparison between results... less variables are a good thing. (For our purpose here we ONLY need the download test, save time and skip the upload test.) Try the mirrors...
...select the mirrors one at a time then retest. Testing across multiple routes can help you discover if the problem is beyond your control. If you get similar results to all US servers the problem is most likely closer to home... possibly within your home network or client machine. If you get slow results to only a few servers you may have a bottleneck or other issue along the route.
Now, see the server with the absolute best results, if this is Dallas look to your second best. Run a multithread test focusing on that server.
Let's remove more variables now that we have a baseline. Take your router out of the equation, hook directly into your computer. Once online disable multithread and test again, the same as before. Improvement will show if the router is to blame. Check cables and connections too. Cables can pass signal and still be bad enough to cripple your connection speed so keep that in mind.
After you run those tests let me know and I'll look at your results again. Just make sure you're signed in so all of your results are saved by username.
