It's like having two squares that are 3 volts tall and 1000 milliamps wide--you can stack one on top of the other to make them 6 volts tall or you could set them beside each other and make them 2000 milliamps wide, but to double both dimensions you'd need four squares...
Oh, man, that brings back memories. Kinda unrelated, but I can't help but be reminded of the old short-wave, packet modems. Been many years since I was into that stuff, but it's a very similar description. Only 300 baud, which gave an illusion of slow, but you could move a massive amount of data through in that same window (virtually unlimited "width," so to speak), unlike with phone lines or cables, which no matter how fast they get are "narrow." Wow, spiffy flashback.