Do USB audio devices need more juice?

Yes, the CPU runs the audio processing when using a USB sound system. Heavy loads on the CPU will affect your sound in some setups (faster processor will have less affect)

USB devices will compete for bandwidth if connected to the same USB root. I am pretty sure that if you are hooked up via USB 2.0, that it would take a lot of activity by the other device, as the standard audio use is at the USB 1.1 level, much less total bandwidth than available. Though I guess if the USB Disk is hogging the whole bandwidth, then you audio might be disrupted.

I am using an M-Audio Transit on one of my systems, and a Headroom USB dac on my other and have no troubles so far, but then I have some nice processors on both of those machines. Come to think of it, I can play WoW and listen to foobar with a Total Bithead in USB mode from my laptop, and it only sports a 1.8 centrino, not a heavy hitter by today's standards. I have no trouble with this setup, even with a USB drive as the music file source. (I use an external USB hub powering the drive, TotalBithead, and the mouse)

Check your machine for malware, clean up your system, you might have better luck. Most folks are having pretty good results with a USB system.

A CPU-intensive task can affect PCI-based devices as well (the player application that drives them needs CPU time).

By the way, I routinely play games like World of Warcraft in high resolution with music playing in the background (via Foobar2000) and never experience audio glitches with my USB device. In fact, I generally always have music playing while using my computer (including during CD ripping / FLAC encoding, another extremely CPU-intensive task). And at work I'm often compiling/linking huge programs (and running them...these are video games, by the way...) while listening to Foobar2000 with my Total Bithead (a USB device). I don't remember having problems with my PCI-based devices either.

However, I know that sound mixing doesn't work very well during games (e.g. playing a game with music and other sound effects while also using Foobar2000 w/ ASIO output at 44K)...perhaps the sound mixing in Windows is more sensitive to CPU usage.

1. Yes.
2. They're trying to sell stuff...
3. No, but it means one more bottleneck for your CPU.
4. Try messing with PCI/PnP settings in your BIOS, and PCI latency.

I generally have to reset my PnP stuff in the BIOS several times after a wipe of BIOS settings, before mine (in sig) will consistently output w/o skips. Since high CPU use does not seem to affect it so much as task switching, and I can get it fixed by resetting the PnP stuff in the BIOS (ESCD? Something like that), I'm guessing it's more of PCI/DMA problem than USB one. USB probably makes it more apparent, though. Also, the problem is not OS-specific. Ubuntu, Source Mage GNU/Linux, and straight-up Debian Sarge are almost as bad as Windows when it's not doing right.

Usually, due to the latencies of the drivers. An efficient driver should not require as much.

Why disclose a weakness? They want to sell this stuff.

They can certainly compete for CPU cycles and DMA cycles.

Do ALL of the things listed on the Computer Audio page of my website under "Pops and Tics":
http://www.empiricalaudio.com

I have played with buffers in foobar and they didn't have much effect. The things that help the most are on my website. Depending on the driver that you are using and the speed of your CPU, you may not be able to run anything else except Foobar. I can run iTunes to an Off-Ramp WiFi at the same time and also write a CD-R without any ticks...

I ONLY use Foobar 0.8.3, along with ASIO SSE2 version 47A and SRC to get the best-sounding 24/96 that I have heard. I put these on a CD-R with all of my products. The newer versions just dont sound as good to me.

Steve N.
Empirical Audio
Manufacturer

Just a point of contention on Foobar version...I have both 0.8.3 and 0.9.4 installed and running on my computer, and I can't hear a difference between them. On the other hand, I'm not using the Secret Rabbit resampler with my Lavry DA10 (it works fine at 44K), so maybe that is the key to the difference between the two versions.

By the way, regarding my comments of not having any problems with my USB sound device even when playing music in Foobar2000 and playing World of Warcraft at 1600x1200 resolution in a window...yeah, I have a dual-core AMD X2 4800+ processor that is overclocked a bit, so maybe that helps.

Personally, I think the sound drivers are the key to most of these issues. I've had the best luck with M-Audio (Transit and Audiophile USB) and E-Mu drivers. If you are using an M-Audio USB device, make sure you are using the very latest version of their drivers, by the way (previous versions had some serious problems, which I think is the source of most of the problems sited in unfavorable reviews of M-Audio products here and elsewhere).

If you mean the player's buffer, no. Unless it's in the single digit milliseconds, it shouldn't have a noticeable effect. The latencies involved are lower level than the application. However, if ti does make a difference, then chances are using a USB drive for the music storage is a major part, and it's trying to send data to the audio device at the same time as reading from the drive.

If you mean ASIO's...I dunno.

Also, almost as an aside, note that this is much more common than you're heard it. Typical PC speakers will "cover up" short gaps in audio playback.