Wow.
Download 420KB/sec.
Such a Speed should come from a 4.2Mb/sec. Cable Internet Connection.
One of the fastest I ever saw.
1.5Mb/sec. should yield about 150KB/sec. Download.
The Rule of thumb is:
Internet Bandwidth (Speed) in Mb/sec. = Download in KB/sec. x 10
B=Byte. b-bit 1 Byte = 8 bits.
So Jack why you are saying x 10, and not x 8 ?
ISP's contracts do not define what you get from your specific computer, but rather defines what they pump into the connection at there end of the line.
The x10 is used in order to infer what would be the actual "Speed" that your ISP is providing.
The "Functional" speed depends on a lot of other components and related to the quality of the connection all the way between your ISP and you Hard Drive.
Usually there would be at least 20% over head.