The ubiquitous USB marches on. The current “480 Mbps” wireless USB doesn’t achieve speeds anywhere near the quoted spec. That’s why although 1 Gbps wireless USB 1.1 will probably achieve nowhere near that spec either. However, considering how poorly Bluetooth has turned out for most computer peripherals (save headsets), I’m hoping the new wireless USB delivers on the promise rather than force companies to use their own RF to get decent mouse response.
On the corded front (and wonder be, we don’t yet have some idiot analyst proclaiming corded USB dead yet), USB 3.0 will have speeds in the ball park of 5 Gbps, be backward compatible (yay!), and use optical cable technology. That all sounds good for the most part, but the optical cable aspect troubles me a bit. That would make the cables rather sensitive to bending, perhaps snapping under duress.
Meanwhile, Firewire hasn’t completely stagnated. The next version should support at least 3.2 Gbps and proposals for 10 Gbps are in the works. That be fast mateys (ok, a day late). Firewire has been far better about achieving and maintaining its spec speeds, meaning that we’ll have to wait and see testing before we know which one will be best for data transfer.
[via Digital World]
>=3 GBps FireWire is vaporware, though. No one's producing 1394c chipsets. Given Intel's USB investment, that probably won't be an issue with USB 3.
First off, optical cables are pretty sturdy, and are remarkably flexible. Do you worry about breaking the optical cables in your home audio setup? If anything, the weak part of the connection will be in keeping the ends of the cable clean, which, if dirty, can halt all communication across the optical fiber.
Second, the notion about USB speeds: I've posted on slashdot about this, so let me just reprint that here. It should explain the discrepancy that people see:
... When the spec states that information flows across the bus at 480 Mbits/s, that means that the frequency at which the bits toggle on the line is 480 Mbits/s. For data to be sent across a USB line, the host must first initiate the transfer with a 'token' packet, which is about 2.5 bytes. There has to be about half a byte of 'delay' on the line after that, at which point the sync for the data packet can be sent, which is about a byte. Only at this point can the actual data be transmitted. But it's not even that easy, because the data is NRZI-encoded and bit-stuffed as well. This is why there's a lot of CPU overhead with USB data transfers - the CPU has to decode the data packet. After the data packet is sent, there's at least 3 more bytes of stuff that needs to happen before the entire transfer is complete.
There's even a limit on the size of the data packet: in USB 2.0, for a bulk transfer (i.e. when you're copying a file to/from your external drive) the maximum data that can be transmitted in one data packet is 512 bytes. And there's no guarantee that you'll even be granted a data transfer at a constant rate - it's completely up to the host controller how often it'll ask the device for a data transfer. If there's a lot of devices contending for the bus, your up/download rates will suffer.
There's a lot of necessary overhead inherent in an asynchronous communication protocol, especially one that grants you the ability to put multiple devices on the same bus. End users need to understand that data does not magically "pop" from one end of the cable to the other, and wherever there are different people implementing the same spec there will be slight differences in how the devices end up working.
That's why Firewire is so much better than USB -- it is synchronous -- that is, the computer AND the device talk to each other, unlike USB, which is always holding a lonely, one-way conversation.
So those of us used to using FW do expect data to magically "pop" from one end of the cable to the other :)
@Ron: I do agree that FW is *much* better in practice. So the main reason for USB being slower is the overhead that comes from allowing multiple devices to be on the same bus. I believe this fundamentally flaws USB, because in practice who really uses USB hubs? I find that people tend to keep one device per USB port on their computer, defeating the purpose of USB. And it's these kind of connections that FW does so well.
Disagree on the USB hubs. There are so many reasons to NOT be able to assign one device per USB port. On most laptops, one is limited to 2 ports. With extra items like external back-up drives, add-on bluetooth dongles, keypads, mice and printers, just how does one do this without a USB router?
Personally, my Firewire port gets the nod for exclusive functions such as bootable drive units, and yes, it has never let me down with respect to transfer speed. You gets what it says.