[linux-audio-user] Just how bad is USB audio?

[Dan Armak]

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Hello,

I'm considering buying a USB sound card for my laptop. (I have no desktop box 
worth talking about atm.) Everyone says a USB card is a Bad Thing, but I've 
found few numerical measures, and I don't have much of a choice anyway 
(unless someone releases a firewire card, or a pcmcica one under $1000)... If 
someone can point me to some more concrete data, it would help me make my 
choice. (Which is basically to buy or to suffer crappy sound, as I see no 
real alternative...)

CPU utilization is the main problem. I probably wouldn't count as a hardcore 
gamer, since I have a p3-900 with 256mb ram and it's enough to run all the 
games I need (mostly ps1 emulations, but some sims/fpss too). So what 
performance hit should I expect from using a usb audio device? The only 
review on the net that actually mentioned numbers was one of the Extigy on 
Tom's H/w Giude, and it said 20% cpu of a p4-2Ghz, but that was using 6 or 8 
channels with special effects requested by something on the order of UT2003, 
which is out of my league anyway.

I don't have or plan to have any other high-bandwith devices on my usb (1.1) 
bus, just a keyboard/mouse/joystick. Also I only have 2 speakers atm, so I'll 
only be streaming two channels. Therefore bandwith shouldn't be a problem as 
I understand it.

OTOH I'd want to do some none-cpu-intensive work (writing, reading) while 
listening to mp3s and copmpiling stuff in the backgruond. I would probably 
accept some slowdown in the compiling, as long as the audio didn't skip and 
responsiveness wasn't affected (I already use a kernel with all the low 
latency/preempt/O1 scheduler etc. patches and have a prelinked system because 
I really hate responsiveness issues)...

Finally as to the card itself: AFAICS there are the costly ones (Extigy and 
Audiotrak Maya 5.1 usb), which have lots and lts of features most of which I 
don't really need, and some cheap ones like the iMic or Xitel Hi-Fi-Link 
which only have stereo rca input/output. The latter type is much closer to 
what I'd be using of all those features, but unfortunately I cannot find them 
in any shops here in Israel, and if I order over the internet I'll have to 
pay for shipping and won't have warranty coverage. So I'd be willing to pay 
for the maya card if I cuold be sure I'll be using it well, preferrably also 
when I build my next desktop system in a year from now.

Any recommendations, info etc. will be most welcome :-)

- -- 
Dan Armak
Matan, Israel
Public GPG key: http://www.gentoo.org/~danarmak/danarmak-gpg-public.key
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