DO NOT buy anything FireWire, unless you like to have the same computer to the end of your career. I built new computer, wanted to use my Presonus StudioLive 24 mixer, but the FireWire did not work on the new computer because Presonus did not sign the drivers. With Windows 10 July 2016 release, all drivers have to be signed. Presonus (for example) signed all drives except first Studiolive release and now I have dead gear that I can not use. Asuming the RME signed the driver for this device, when you buy new computer in the few years, the drivers for FireWire cards may not be signed or it may be hard to find FW400 card compatible with latest Windows update. Windows is volcanic right now, everything changes rapidly. I would not risk. I am actually shopping for new interface as well BECAUSE of FireWire issue with Presonus. These are recommendations posted to me http://forum.cakewalk.com...-m3580258.aspx#3581013

Sylvan
I am the proud owner of a RME Fireface UFX. I can't think of ever using anything else, it is that good. Of course I add other stuff to it for extra inputs, like the Tascam US 20X20, 16X08, and the ART MPII via AES, but the UFX remains the centerpiece of my operation.
 
I operate in a commercial capacity recording full bands with full drum sets, amplifiers, keys, etc... I have plenty of inputs, can send individualized headphone mixes with zero latency to all the musicians using the TotalMix software. I have used all 30 inputs simultaneously without a hiccup.   

This is interesting. How do you connect Tascam US 20X20, 16X08, and the ART MPII via AES? What is AES? I know that with ASIO driver, only one interface can be connected at a time, unless they are the same Brand and chain connected like via Thunderbolt. Please, elaborate. Thank you.

AES/EBU is another digital standard like S/PDIF or ADAT lightpipe. I've never used it but it uses an XLR connector and I think it's only stereo so probably he means hooking up the Tascams over ADAT and the Art MP over AES.

I was always wondering why they still use ADAT ins and outs- who in the world still uses the ADAT tape? And how is MADI works?

Nobody uses the tape but it's a convenient standard still, you can get plenty of 8 in, 8 out converters in various price classes.

I've been using RME for almost 10yrs "Rock Solid" performance, clear beautiful sounding audio interface.

vladasyn
I was always wondering why they still use ADAT ins and outs- who in the world still uses the ADAT tape? And how is MADI works?

I bought into ADAT a long time ago as 'speed of light' seemed pretty darn quick.
So, I'm ADAT out of my mixer into ADAT in on my PCI-e sound card. 
If there is a faster (lower latency) way, I'd like to know.

It has virtually nothing to do with latency.

you won't get a latency reduction with ADAT vs USB, afaic (ADAT is a cheap way for manufacturers to get a lot of extra channels).
furthermore ADAT is limited to 48k sample rate iic
have you checked out the RME fireface 802 ?  (specs are somewhat simular to the UFX) 
that could save you a few hundreds....if so, drop me 100 ok ? 

ADAT can handle 48KHz, 96KHz and 192Khz. The catch is that if you have 8 ADAT channels at 48KHz that reduces to 4 at 96KHz and 2 at 192KHz, at least it does the way RME does things. Basically to get the higher sampling rates ADAT channels get merged to increase the bandwidth.

Personally I'm happy enough at 44.1 or 48KHz most of the time.