USB 2.0 does 96Hz?


I have heard a rumor that unlike USB 1.1 which is limited to 48Hz, USB 2.0 will transmit up to 96Hz. True?
mmarvin19
Scrith -- It would be computer-dependent. USB relies significantly on processing by the cpu and its associated chipset on the motherboard. I would expect that a modern well-tuned computer with adequate memory will have no problems, but a computer which is bloated (as many are) with large numbers of useless background processes, and is configured with too little memory to support them optimally, and/or is running resource-hogging Vista, or is old and does not have typical contemporary computing horsepower, will have problems.

Firewire, in contrast, shifts most of the processing associated with the interface to the interface chip itself, and guarantees that the data rate will never fall below a certain amount (which was chosen to assure that the DV format (Digital Video, for which the data rate is much higher than for audio) could be transferred without interruption).

In response to your closing comment, btw, in my case I did not claim that "USB can't support 24/96," I just said that I would not be surprised if it (USB1.1 specifically) were to intermittently break up. I should have added to that statement the phrase "depending on the computer."

Regards,
-- Al
I'm using 24/96 over USB 1.1 without any problems with both my Benchmark DAC1 USB and my Ayre QB-9.

Perhaps those who are claiming USB can't support 24/96 should give some examples of the problems they've personally had when trying to use it, assuming they actually have any experience with it at all. :-)
USB should do 24 bit at 96khz, but it is not very stable.

Benchmark and Wavelength are both using USB at 24/96 with good success. In running high-rez flies into the Benchmark I have not had a a problem or instability ever.
USB should do 24 bit at 96khz, but it is not very stable. You are much better off going to firewire, or use a pro card that has AES/EBU digital out to connect your DAC to.

Apogee and others have dropped their USB 24/96 converters due to issues with the signal.
Thanks for the replies.

Me Bad - I forgot the "k" in "kHz". I must have subwoofers on my mind.
I never had any problems streaming 24/96Khz data to my Benchmark DAC1USB using the USB1.1 protocol. USB 2.0 is supposed to go up to 192KHz with the right drivers and hardware.
USB will do 24/192. Just needs the right hardware and driver.

Steve N.
Empirical Audio
USB1.1 has a maximum data rate of 12 megabits per second, or 1.5 megaBytes per second. USB2, which was introduced in 2001 and is present these days on most computers and most devices that have usb ports, has a theoretical maximum data rate of 480 megabits per second, or 60 megaBytes per second. Real world data rates for USB2 are significantly lower than that for various reasons.

Not sure what your references to 48Hz and 96Hz mean. Those are deep bass frequencies. If you are referring to 48KHz (note the "K" for kiloHertz) or 96KHz sample rates, both are within the theoretical maximum bit rate of USB1.1, but as a practical matter I would not be surprised if USB1.1 could not handle continuous streaming of 96kHz 16 or 24 bit audio without intermittently breaking up.

Regards,
-- Al

Regards,
-- Al