Soundcard or audio interface?

Hi folks

Just wondering about your thoughts on the advantages/disadvantages of using a soundcard or audio interface for recording?

I know technically they do the same thing but I'll probably be getting a new PC soon and I was wondering whether to stick with my Audiophile 2496 (which is pretty old now) or go for an external interface like a Focusrite. 

What are the differences between the two approaches? Do they effectively 'work' the same way?

Many thanks 

YC

Focusrite has relatively nice onboard preamps/converters... but lowest possible round-trip latency is not their forte'.  

I have a Focusrite Scarlett 18i6 and it definitely doesn't beat out some of the competitors like MOTU or Roland (from what I've read anyway) when I set it to the lowest setting I'm getting around 7ms roundtrip which isn't noticeable at all for tracking (to my ears anyway). I probably wouldn't be able to get away with that with any less computer horsepower though and I have to increase the buffers slightly to avoid weirdness when using some of the heavier duty effects in Sonar.

The mic pres are very nice sounding and the unit hasn't given me any problems at all since I bought it. I could record a full band demo or properly mic up an entire drum kit with all the analog inputs if I want (need a mixer though). I can get even more inputs if I use a second box like a mic pre or my Echo Layla via the optical connectors.

But, as I said I have a pretty decent system. i7 2600k, 16GB RAM, 7200rpm HDDs, optimized for audio, etc...

Not really directing that at you, Jim as I know you know what's up. Just wanted to give some insight on the Focusrite stuff from a happy user and expand on your statement.

Essentially... yeah, not the fastest interface but with my system which is nice but not crazy it works great without any noticeable latency. I probably would have had to spend at least twice as much to get something in the ultra low latency realm that did as much as much and sounds as good as my Scarlett does.

Another advantage of a USB interface is you can plug it into other systems easily. Another reason I wanted a USB device. It lives on my big rig but I intend on using it with my laptop when I need to record somewhere other than my "studio".

I'm not a tech or pro engineer though so YMMV.

The 2496 is a good card--the first I bought after ditching my soundblaster back in the dark ages. For my uses it is more than adequate, since I actually do very little recording, and mostly just need clean playback of softsynths. At some point is will certainly become obsolete, as boards do not support the interface or the drivers stop working on new systems. One advantage of an external interface is that it is more likely that USB will survive into the future than PCI. You will probably be able to buy add in cards for firewire interfaces for a while, but that is a dying protocol and will probably be disappearing from motherboards before long, like legacy PCI. But if you are doing a lot of recording, you will probably be wanting more inputs in the future than the 2496 provides. There is little to be lost in delaying your upgrade until you do.

I got a new one a couple of years ago, I settled for RME after using Rolands, Motu and RME for 20 years.
PCI or Firewire was my question and even the guys at RME said that PCI is great, but the new USB drivers they developed are as good as you can get (FW is dying they said). So I got this RME UC and must say that, by all means is better than the MOTUs I was replacing and at the same level (latency etc)  of a Hammerfall (RME 2496 pci) I use in another studio.