Really? Well, im not making it up (nor discounting your experience), but I've had it that fast for years.
You don't have a connection that does 2.4GBps or even 2.4Gbps down. At the absolute best, you have a 1Gbps NIC in your desktop, so that alone would be limiting you if you would be able to somehow saturate it.
Also, Comcast operates on DOCSIS v3.0, which has a hard MAX of 117.18Mb/s (14.65MB/s).
Also, even with SSDs, you can only get 200MB/s in theory. A couple of those in RAID0 might get you to 300MB/s in theory, with a very good RAID card behind them.
You're either lying, or just don't have a clue what you have for technology.
Go here: Speedtest.net - The Global Broadband Speed Test
Run the test
After it's done, click the "Share result" link, and paste the image here.
Here's mine, just as an example:
http://www.speedtest.net/result/1242611420.png