How does an audio interface make my DAW faster?

[sporkit]

Hi Everybody,

I have a reasonably fast Windows PC coupled with a FirePod FP10.

Currently the FP10 is being sent back to PreSonus for repair (don't plug your firewire cables in backwards). I'm trying to work on my house music, but the computer grinds to a halt when hitting some of the more intense software synthesizers (even if I have asio4all running).

That got me thinking about something I've always wondered. How does my audio interface help speed up audio processing? How does my setup know the difference between an audio calculation and a software calculation?

Is my on-board audio card really all that different from an expensive audio interface?

Lastly, can anybody suggest a reasonably priced hi powered sound card or audio interface that will help me get the most out of my current system?

[BertKoor]

It's a moot point nowadays. Processors are fast enough. If you save something this way, it's less than one percent: not noticable in real life.

The theory is that it takes barely any to no CPU cycles at all for a PCI(e) card to communicate its audio buffers from/to memory. The PCI bus basically has direct access to that, the card works autonomous, no need for the CPU to intervene.
In contrast, USB devices cannot do that. USB needs the CPU to transfer all the data to/from memory. And it's a serial protocol, meaning that every small packet with data adds some overhead, making it an inefficient protocol for continuous data streams.
But you have FireWire. That protocol is designed for streaming, so the inefficient packet overhead is totally absent.

So if your machine is a laptop, you can't do any better than you currently do. Stop worrying. Freeze some tracks you're not working on, or use synths/effects which are less demanding.

[tenshin111]

That got me thinking about something I've always wondered. How does my audio interface help speed up audio processing? How does my setup know the difference between an audio calculation and a software calculation?

Well, it doesn't. It's not another graphics accelerator. All the processing required by your DAW / plugins is done on your CPU, it is not hardware accelerated by the soundcard.

Sure, there are systems that use dedicated chips to offload signal processing - you could look into that, for example UAD, Creamware Soniccore or Pro Tools HD. These are costly solutions though. Besides, in case of laptop computer the choice would be very limited anyway.

[sporkit]

When my FirePod is plugged in I notice it takes about 30 seconds to convert a song from wav to mp3. Now that it's at the shop it seems to take twice as long. Even in my DAW I notice freezing tracks seems to go much faster. Maybe these differences are in my head?

The Wikipedia entry for ASIO states "ASIO allows musicians and sound engineers to access external hardware directly". I thought ASIO allows me offload some kind of audio processing to the hardware interface itself?

I know one thing for sure. When I get my unit back. I'll be comparing the differences with it plugged in and not.

[ZenPunkHippy]

I thought ASIO allows me offload some kind of audio processing to the hardware interface itself?

This is a common misconception because we are used to graphics cards improving the frame rate of games.

It's not the audio card itself that improves performance but the quality of the drives. The sound card itself does not do any DSP processing unless you have something like the UAD system.

Some companies write inefficient drivers, some companies write very well optimised drivers. This will have some impact on latency and the number of plugins your CPU can handle.

Peace,
Andy.

[BertKoor]

When my FirePod is plugged in I notice it takes about 30 seconds to convert a song from wav to mp3. Now that it's at the shop it seems to take twice as long. Even in my DAW I notice freezing tracks seems to go much faster. Maybe these differences are in my head?

Probably yes... The processes you mention are absolutely independant from your audio interface. You can do them even without any audio devide (provided your DAW loads without)