[citation][nom]fooldog01[/nom]Call me crazy but I dont understand why they dont overkill these standards. Why isnt the new USB spec like 20 Gbit/s? Is that technologically out of reach? Why aren't they doing a little more to future proof this stuff? With SSD's on the rise, that bandwidth is going to feel strained in a relatively short time.[/citation]
Geez, don't neg-vote the guy for saying something like this, he may very well not understand.
fooldog, these speeds are not chosen arbitrarily, but are based upon the current limitations in the technology and some attempt at prognosticating where the technology will likely be when the standard actually becomes a standard.
Without getting into technical detail, consider the evolution of data transfer rates for hard drives. Forgetting all the MFM and RLL stuff, and jumping right into IDE. Initially, data transfer was controlled via PIO modes. The limitation here was that it required the CPU to be involved in data transfers, and when the amount of data was particularly large, it imposed a tremendous load on the CPU. Then came DMA modes, which allowed data to be written directly to memory without putting a huge burden on the CPU (those were ATA standards 1 and 2). Then came more DMA modes, then Ultra DMA modes. We went from ATA-1 at 3.3 Mb/s to ATA-7 at 133 MB/s (theoretical). Now why not just create ATA-7 well in advance of needing that much? Because it was technologically impossible at the time. The technology simply did not exist.
It's just like the CPUs, we hit 500 MHz back in 1998, 1 GHz back in early 2000, 2 GHz in late 2000, then it wasn't until 2005 that we hit 4 GHz, now a few months shy of 2010 and we're still hovering around 4 GHz... WTF is up with that? We should be pushing 10 GHz by now. Well, we hit the wall. We're up against the theoretical limit of the technology and no one has come up with the next trick yet. So instead of going faster, they started putting more cores (essentially multiple processors) on the same chip.
I'm sorry, this is longer than I wanted it to be. The bottom line is that creating a standard is no easy task. There are a multiude of factors that have to be taken into account. Anyway, I hope this helps.