I have used SONAR 8 with a Fireface 800 (10 channels and an ADA8000 (8 channels) to record live for as long as 7 continuous hours with a total of 18 tracks simultaneously.
The 2 devices were connected via Wordclock with the FF800 providing the timing as the Master Clock device. This project was set to 24bit 48 khz.

I used a 16 channel mixing desk for the live mix. It had a level adjustable (pre fader) direct out on each channel feeding 8 inputs on the FF800 and 8 on the ADA8000. The other 2 channels on the FF800 were a "Control room" (copy of the live mix) mix, from the desk. So I had 16 channels of individual instrument and vocal tracks and a 2 track (not stereo) live mix recorded.

Because I knew the format of the concert and there were breaks for setting up different performers, I preset a number of projects with my (previously made) live mix template and took advantage of the breaks to quickly save and load a new project. This provided redundancy in that saved projects were generally safe from corruption should a severe crash occur or power failure etc. Remember SONAR was only acting as a digital recorder not a live mixer or monitor. It could have been but my priority was providing a live mix while recording it was of secondary importance.

When sampling at 48,000 times each second (just as an example) its important for the 2 devices to be timed from the same clock.
You can imagine the problems if the sample rates aren't exactly the same and the timing of those samples is also not precise. There will be timing differences occurring between 2 separate input paths and any drift that occurs may also not be at the same rate on each device.
There'll be problems lining tracks up and maybe even phase issues etc.

I used a DELL Laptop, Core2Duo 2.66 ghz CPU 4 GIG RAM WIN XP Pro SP2 using external eSATA 160GIG Samsung 7200rpm HDD.

The FF800 comes with a mixer software interface called TotalMix. Most sound cards have a mixer applet as well as a control applet. When you use 2 separate firewire devices, even connected in a daisy chain they don't really see each other.
When you use, like I did, a sound card with an ADAT device connected, then the devices appear as one. The computer sees the (in my case) FF800 and the ADAT connected to it as a number of identifiable inputs and outputs without even needing SONAR to tie it all together. Hence I could record and or mix and even monitor with Zero Latency if I chose not to use SONAR.

i use the motu 896mkv2 and with light pipes add two 8-pre units for 24 channels up to 96khz. never had a problem in 7 years.  with new SDD hardware its been amazing, load and save times are instant. sonar x2, build a good system to support your datastreams and encoding.

mashU2BITs
i use the motu 896mkv2 and with light pipes add two 8-pre units for 24 channels up to 96khz. never had a problem in 7 years.  with new SDD hardware its been amazing, load and save times are instant. sonar x2, build a good system to support your datastreams and encoding.

Ok. That thread was two years old already when you started with your system seven years ago :o)

Kalle Rantaaho
Ok. That thread was two years old already when you started with your system seven years ago :o)

And yet the question - and answer - remain relevant 9+ years later.
 
So many questions persist year after year, and it's surprising how rarely their answers have changed over time. 

Fog
like with the motu's years ago.. they had a pci card slot, but you could plug 3 into that card.

This is great.  From 2009 and the motus are already "old".  Well it's 2018 and I'm *still* using my 3 MOTU 2408s for 72 channels digital I/O no problems.