I myself would consider that to be about normal. I would'nt DN/LD 4 Video Files at once though.
There are a lot of variables when it comes to Maximizing Speed. You might just play with the settings and see what works best for you.
You can do a speed test here.
Speedtest.net - The Global Broadband Speed Test
Try downloading a file from this site & see how fast it downloads.
Magnetmix 