[LAU] Neophyte questions re: selecting an audio interface

[Clemens Ladisch]

Chris Metzler wrote:
> PCI
> ---
> Cons:
> - Outdated technology -- PCI slots being slowly phased out of modern
>   motherboards

In the consumer space, sound cards are switching over to PCI Express.

I'd guess everybody is waiting^Whoping for VIA to create a PCIe version
of the ICE1712, but it looks as if VIA doesn't think this would be
a valuable market.

(None of ESI's PCIe cards work with Linux.)

> - Latency tuning possibly required (identifying IRQs associated with
>   PCI slots and picking slot accordingly)

USB and 1234 controllers are PCI devices too, so you have exactly the
same IRQ problems, except that you cannot change the slot of an onboard
device.

> - Computer-caused interference noise possible unless audio converted to
>   digital domain outside computer

I don't think this is a problem in practice.  I've never heard of actual
noise problems of PCI audio interfaces; all the reports I did hear were
from cheap USB devices that picked up noise from the computer's power
lines.

(Asus and Creative are in a fight over who can build the sound card with
the highest SNR value, and achieve 118 dB when recording, but these
cards are designed for "HiFi enthusiast" consumers.)

>   ==> breakout box.  But PCI interfaces with breakout boxes tend to be
>   pretty expensive.

It's cheaper to design and build the card to be noise resistant.

>   OTOH, no breakout box = lots of cables going to the back of the
>   computer.

I suspect this is the actual reason for breakout boxes.

> USB
> ---
> Cons:
> - A single 24/96 channel means 2.3Mbps; 12Mbps nondirectional hard
>   limit under USB 1.1 so only 2 channels full duplex,

USB has lots of overhead.  It can just barely fit eight 16/48 channels
into USB 1.1; full-duplex 24/96 is not possible.

> 1394
> ----
> Cons:
> - Long-term viability of 1394 interface?  Will my next computer have
>   one?  Will a future laptop?

High-end mainboards still have a 1394 controller chip among their many
bells and whistles.  In any case, controller cards will still be
available (as PCIe or ExpressCard).


Regards,
Clemens