DSP in audio interfaces and Plugins.....???

[Chew_Bear]

So...I am a little confused about DSP in general. Especially...when a manufacturer advertises or claims that they have DSP inside their audio interface.....

1. What's the purpose of having DSP inside an audio interface...??? Does DSP take away extra "strain" and work from your computer's CPU and therefore plugins/VSTs operate and perform more efficiently thereby reducing PDC and latency...???

2. Can any plugin/VST "harness" or use the DSP that is inside any audio interface...??? Or can only certain plugins access a certain manufacturer's interface/DSP...???

So in conclusion...

Can a very fast and powerful CPU/computer handle all the necessary plugin/VST processing, thereby eliminating the need for DSP all together...correct...???

Would there always be a need for some form of DSP in your setup/workflow...if your computer's performance is slow and therefore your plugins/VSTs are slow or have high latency...???

 

[krushing]

1. What's the purpose of having DSP inside an audio interface...??? Does DSP take away extra "strain" and work from your computer's CPU and therefore plugins/VSTs operate and perform more efficiently thereby reducing PDC and latency...???

Yep, the purpose is to offload the processing to the DSP unit. So theoretically (and yes, in practice as well), you'll get more free CPU time for other stuff. PDC and latency aren't magically erased though - on the contrary, you still have to stream the audio data to and from the DSP thingy, which both causes latency on its own and demands some CPU resources. In practice though, it's not really an issue anymore.

2. Can any plugin/VST "harness" or use the DSP that is inside any audio interface...??? Or can only certain plugins access a certain manufacturer's interface/DSP...???

No. There are no "general" DSP platforms at the moment, only proprietary ones - and not too many of these either. Universal Audio's UAD is probably the most well known, Avid's high-end Pro Tools HDX systems are another, and well...then there's stuff like Sonic Core's (formerly Creamware) SCOPE (which I'm not really sure if it's even being developed anymore). That's about it. There are a few hardware VST players, most notably Muse Research's Receptor and the SM Pro V-Machine, but frankly neither of these are really meant to be studio DSP solutions but rather intended for using plugin instruments and fx in a live setting.

So in practice, for the home recordist, there's UAD and not much else.

 

[Chew_Bear]

Thats what I figured browsing audio interfaces and plugins/DSP on sweetwater, B&H and other music e-tailers.

That the only DSP worth getting for a home studio would probably be the UAD interfaces and their respective plugins...if taking extra strain off your computer's CPU was a major concern/factor.

What about MOTU, Roland and Steinberg....???

Some of these manufacturers also advertise DSP as being inside their interfaces also. (828x, Octacapture, UR824 etc)

So...my guess is that you can only use the specific plugins that came with that specific manufacturer's interface...just like the UAD plugins can only be used by a UAD interface...correct...???

 

[krushing]

Thats what I figured browsing audio interfaces and plugins/DSP on sweetwater, B&H and other music e-tailers.

That the only DSP worth getting for a home studio would probably be the UAD interfaces and their respective plugins...if taking extra strain off your computer's CPU was a major concern/factor.

Frankly, nowadays, even not-the-highest-end computers can run an immense amount of mixing plugins. Maybe not a gazillion instances of the latest and greatest synth plugins, but frankly I think UAD's selling point these days are about the supposed authenticity of their plugins and emulations rather than just freeing CPU resources. And as said before, there isn't much choice besides UAD.

What about MOTU, Roland and Steinberg....???

Some of these manufacturers also advertise DSP as being inside their interfaces also. (828x, Octacapture, UR824 etc)

So...my guess is that you can only use the specific plugins that came with that specific manufacturer's interface...just like the UAD plugins can only be used by a UAD interface...correct...???

Pretty much, yeah - and I'm not sure if they're even usable as mixing plugs (this is something that some interfaces might offer, some not...), but rather they have a handful of plugins that can be used "latency-free" in the monitor mixes, so you can (as a simplified example) have reverb on your vox while singing without having to go through the DAW. And as you guessed, these only work with the interfaces they come with.

Practically every interface has some sort of DSP chip in it, if only for internal routing and mixing. So just because something "has DSP", it doesn't necessarily mean much.

 

[Chew_Bear]

Ahhh finally I get it now. Thanks Krush. You da man!!!

 

[Chew_Bear]

I am somewhat still confused and the gears started turning inside my head.....

So...When it comes to the "number" of instances of plugins/VSTs that you can run at any given time during a project/session....*(Depending on your computer's specs and the DAW of course)*....

1. Do certain plugins/VST manufacturers or brands draw more processing 'power' than others and therefore might dictate which plugins and VSTs a newbie might want to buy/purchase or steer clear of if their computer is not up to the task....????

Say for instance a waves compressor takes more CPU power than a Fabfilter Compressor. Should I buy the fabfilter comp that takes less power just because I can have more instances and/or more plugins open...???

2. Does the number of instances I can have open...also have to do with the 'type' of plugin also...???

Say for example a 'mixing' plugin...VS...a 'instrument' plugin. Will a VST synth like NI Massive draw more power than a mixing plugin like a Fabfilter Pro C or whatever and vice versa....???

Or do all VSTs and plugins pretty much draw the same amount of 'power' regardless of brand or type....???

Therefore it all boils down to which process of music production your working in, your workflow and how labor intensive your session is and therefore dictates the amount of instances you can have operating at any given time.

 

[krushing]

Yes, plugins use varying amounts of CPU power (some plugins even have internal quality modes, so you can use a less CPU intensive version of it when composing and then flip it to the best quality when rendering the final track). And well...I guess in some situations someone won't buy this or that plug for this or that purpose because of its heavy CPU draw, but it's pointless to make an umbrella statement about this.

No, you can't generalize between "instruments" and "effects" in this regard. Some instruments can be very light, some very heavy. Some can have, in addition to the aforementioned quality modes, things like Massive's dynamic voice allocation - it'll use more CPU the more polyphony is used.

So basically your questions don't really have a theoretical answer that'd have any practical value; you'll just have to try things out and see what's heavy and what's not. With ever-increasing CPU power it's less and less of an issue though.