usb 1/2.0 transfer speeds...?

[grandkodiak]

I'm thinking for some reason my usb transfers speeds are awefully slow for some reason, but I hate math. i'm copying movies from my camcorder to my pc via usb2.0 and i'm getting roughly 750kbits/s transfer speed. i looked online and usb 2.0 is supposed to be 480mbits/s which is 491,520kbits, no?

at this rate its going to take roughly half a day to transfer a freakin 1.5 hour video. i think professional artists could draw a 30fps cartoon at that length in half the time. wtf?

(and yes the drivers read as usb 2.0 in the sys and the device is a 2.0 camcorder)

[NE-Firebird]

Synopsis: Just because a device is USB 2.0 compatible, that does not mean that it can transfer at the max USB 2.0 rate for any rate of time.

There are many factors involved in bus transfer speeds. I've designed custom hardware buses, and my thesis was on a real-time hybrid networked bus architecture for an imaging system. IMHO, many people think they know about buses and their transfer speeds, but they don't.

With USB 2.0, 480mbits/sec is approx 48MegaBYTES/sec transfer rate. But, if someone REALLY gets even 35MBytes transfer rate, they are doing very good!

You may be getting 750KBytes transfer rate. That's not bad from a camcorder.

As I said, there are a ton of real life factors. Does the camcorder use tape? What's the tapes max xfer speed? Many USB 2.0 chips and USB 2.0 devices have a hard time coming close to transferring at a rate of 1MByte/sec for anything more than ~300 bytes.

The buffers in your PC's USB chip and the devices USB chip make a big difference. Also, how fast your PC and how fast the devices CPU can respond to requests makes a big difference.

Over the years, I've argued with a TON of people about USB speeds. What ever. There are plenty of performance tests that have been done. I've done a bunch of tests myself with different USB chips and PCs.


BTW: The real life USB xfer speeds with different digital cameras is a huge topic. Plus, the speed of the flash can also effect the transfer rate of the new better cameras.

You can try to do a google search on your camcorder and USB transfer speed. But, all that may tell you is that the real life USB transfer speed is poor for your camcorder (like it is for many camcorders).