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How many simultaneous tracks can you theoretically get via FireWire?
Old 5th February 2010
  #1
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Myr's Avatar
 

How many simultaneous tracks can you theoretically get via FireWire?

I just ordered a Saffire 56, and I noticed it has multiple ADAT ins. How many tracks does the FireWire standard support, especially at higher samplerates?

I'm currently tracking 24/44.1 around ten tracks, and this works fine, I'm just worried that my new 16 track setup @ 24/88 will output too much bandwidth.
Old 5th February 2010
  #2
Hi, I'm using a older Focusrite safire 26 IO pro with a Behringer ADA8000.
Sofar i've tracked a session with 14 simultanious tracks at 24 bit 44.1Khz with no problems. This with an old P4 toshiba laptop, so no problem.

By the way firewire bandwith is suffient enough to get 32 tracks in and out simultanious (these are specs!)



Menoj
Old 5th February 2010
  #3
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You should be able to get all inputs and outputs working at the same time at 44.1k/24bit.

I'd be amazed if any company had released a 'good' interface which wasn't actually able to utilise all inputs and outputs at the same time.
Old 5th February 2010
  #4
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Isn't the answer to this question really dependent on a number of factors (e.g. what you're doing with the tracks (recording vs. playback), how many plugins are running in the tracks, automation, etc.) ?

~Jeff
Old 6th February 2010
  #5
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That shouldn't really have any bearing on the performance of Firewire. Plugins, automation etc... are all to do with CPU and the performance of your computer itself.

Firewire has it's own bus processor (which is independent of your CPU). Audio going in and out is treated the same...
Old 6th February 2010
  #6
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Well, I've always done the math as 5 meg /sec for mono files & 10 meg/sec for stereo files. Using that rationale, You should be able to transfer 40 stereo files or 80 mono Wav files over FW 400. These numbers would theoretically double with FW 800. USB 2.0 has 480 meg/sec transfer rate therefore USB should theoretically handle 48 stereo tracks and 96 mono Wav files. As was already mentioned, it depends on several other factors. Daisy chained HD, record vs. playback tracks and others. Feel free to fire away if I'm way off base here!

Doug
Old 6th February 2010
  #7
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Ive used and audiofire12 with no issues at all...recording obviously 12 tracks at a time....and running over 40 back at a time...so im sure youll be fine unless your looking to run like 100+ tracks...lol
Old 7th February 2010
  #8
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Quote:
Originally Posted by Chunky But Funky View Post
Well, I've always done the math as 5 meg /sec for mono files & 10 meg/sec for stereo files. Using that rationale, You should be able to transfer 40 stereo files or 80 mono Wav files over FW 400. These numbers would theoretically double with FW 800. USB 2.0 has 480 meg/sec transfer rate therefore USB should theoretically handle 48 stereo tracks and 96 mono Wav files. As was already mentioned, it depends on several other factors. Daisy chained HD, record vs. playback tracks and others. Feel free to fire away if I'm way off base here!

Doug
It's possible you've confused the difference between file transfer and audio transmission. USB is actually considerably slower than FW400, despite the difference in measured data-rate, as FW400 is a much more efficient protocol, whilst USB transfers other information at the same time which eats up a considerable amount of bandwidth. Hence, FW400 is far more suitable for recording than USB2.

Quote:
Originally Posted by Janesaid2me View Post
Ive used and audiofire12 with no issues at all...recording obviously 12 tracks at a time....and running over 40 back at a time...so im sure youll be fine unless your looking to run like 100+ tracks...lol
I wouldn't want to do 100 tracks, you'll be pretty far past the available bandwidth at that sort of track count (not that I've ever actually tried). At 100 tracks, you'll have hard-drive issues more than anything else...
Old 9th February 2010
  #9
CAW
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When I do the math on bandwidth per track, I come out with numbers that are nowhere near as bad as the vendors of Firewire audio devices make the world out to be. I honestly think the "must dedicate the Firewire bus to our device" stuff they spout has more to do with their product not playing well on the bus with other devices present than it does because of actual bandwidth. Let's assume worst case, 32bit floats (a few audio interfaces now support this, even if their AD/DA stages are still only 24bit). Since Firewire bandwidth is rated in bits, we don't need to worry about converting that to bytes. So, at a 44.1k sample rate: 32 * 44100 = 1,411,200 bits per second 400,000,000 / 1,411,200 = 283 and change Now, one will never actually get a full 400mbit. There is always some protocol overhead. Let's say FW400 is actually only 75% efficient (which I believe to be extremely conservative). 300,000,000 / 1,411,200 = 212 and change So in a worst-case scenario of 32bit channels (which very few people are using, most will have 16bit or 24bit interfaces), you can theoretically get over 200 44.1k channels on one FW400 bus operating at 75% max efficiency. I've yet to see anyone with an interface that has anywhere near that many channels; such a device would be many U of rackspace to physically fit all the analog jacks (or be nothing but a bunch of ADAT in/out ports). Even the Focusrite Liquid Saffire 56 (which I own) is only 56 channels max -- 28 in by 28 out when operating at 44.1k. The Liquid Mix is a max of 64 channels (32 sends by 32 returns). And I suspect the various Firewire-based DSP systems will run out of DSP before they run out of Firewire channel bandwidth. For higher bitrates: 96k = 97 32bit channels at 75% max efficiency 192k = 48 32bit channels at 75% max efficiency But most audio interfaces drop the number of channels they have as the bitrate goes up. For example, at 192k, the Liquid Mix only supports 8 channels (assuming you've got the DSP expansion card in it). So it is still using the same amount of Firewire bandwidth.
Old 9th February 2010
  #10
CAW
Gear Nut
 

Ugh wow. Sorry for the wall of text. That was nicely formatted when I wrote it, and it seems the message forum here has stripped out all the paragraph breaks.
Old 12th February 2010
  #11
Hi when playing 100 tracks in fact only 2 output port are being transmitted over the firewire cable, the output count regarding firewire bandwidth has to do with physical outputs, playingback 100 tracks is just internal summing to your masterbus. By the way firewire protocol is specifically built for realtime video-operations so very suitable for audio as well, USB being build as a fast serial bus to cover quantity of devices.

Old 12th February 2010
  #12
Gear Maniac
 

I think the highest track count of a firewire device is the M-Audio LightBridge? with 34x36 I/O.

So I think it's about about 72 channels at 44.1/48K 24bit. Halve each time you up the sample rate accordingly.

I haven't seen a firewire system exceed that I/O yet.

We all know the audio manufactures code for their drivers are all horribly unstable, inefficent and suffer from a vast number of issues.
Old 18th May 2011
  #13
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So what is this firewire 400 / 800

I've got a firewire 400 port on my laptop,
I'm assuming that 400 is slower than 800

So how many simultaneous channels could I record into my DAW at one time?
Old 18th May 2011
  #14
restpause
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Quote:
Originally Posted by CAW View Post
When I do the math on bandwidth per track, I come out with numbers that are nowhere near as bad as the vendors of Firewire audio devices make the world out to be. I honestly think the "must dedicate the Firewire bus to our device" stuff they spout has more to do with their product not playing well on the bus with other devices present than it does because of actual bandwidth.

Let's assume worst case, 32bit floats (a few audio interfaces now support this, even if their AD/DA stages are still only 24bit). Since Firewire bandwidth is rated in bits, we don't need to worry about converting that to bytes. So, at a 44.1k sample rate: 32 * 44100 = 1,411,200 bits per second 400,000,000 / 1,411,200 = 283 and change Now, one will never actually get a full 400mbit. There is always some protocol overhead.

Let's say FW400 is actually only 75% efficient (which I believe to be extremely conservative). 300,000,000 / 1,411,200 = 212 and change So in a worst-case scenario of 32bit channels (which very few people are using, most will have 16bit or 24bit interfaces), you can theoretically get over 200 44.1k channels on one FW400 bus operating at 75% max efficiency. I've yet to see anyone with an interface that has anywhere near that many channels; such a device would be many U of rackspace to physically fit all the analog jacks (or be nothing but a bunch of ADAT in/out ports).

Even the Focusrite Liquid Saffire 56 (which I own) is only 56 channels max -- 28 in by 28 out when operating at 44.1k. The Liquid Mix is a max of 64 channels (32 sends by 32 returns). And I suspect the various Firewire-based DSP systems will run out of DSP before they run out of Firewire channel bandwidth. For higher bitrates: 96k = 97 32bit channels at 75% max efficiency 192k = 48 32bit channels at 75% max efficiency But most audio interfaces drop the number of channels they have as the bitrate goes up. For example, at 192k, the Liquid Mix only supports 8 channels (assuming you've got the DSP expansion card in it). So it is still using the same amount of Firewire bandwidth.
THANK YOU... somebody who uses actual factual MATH to get to the bottom of this. I'm glad you took into consideration the bit resolution of the tracks and used a high bit resolution for the example.
Old 18th May 2011
  #15
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Various audio over Ethernet technologies (Cobranet, Ethersound, Aviom etc) max out a 100 Mbit connection at around 64 channels in each direction. These would normally be 48kHz-20 or 24bit tracks. Firewire has 4 times the throughput of 100Mb Ethernet- so we could theoretically send 256 channels of audio at 48/24 in and out of the interface simultaneously.
Old 18th May 2011
  #16
Even if the file format is 32bit float, the fw interface only has to deal with 24bit audio. No interface records 32bit files, that's all in the software.
Old 18th May 2011
  #17
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What is the point of this hypothetical? Hard drives never go as fast as 3G bandwith let alone the 6G SATA ports out there now and the list goes on and on with computer parts. You get what you get and with Firewire audio that isn't much compared to PCI and PCIe cards. A more relevent question would be to list all of the Firewire interfaces that can do a stable 16 I/O at low latency under full load (this is going to be a real short list). As others have mentioned it's just as much about the drivers as it is the hardware end. If you are looking for real life 24 I/O or above then forget about Firewire.
Old 23rd December 2012
  #18
Doug aka Chunky but Funky... it's actually 10megabytes/stereo MINUTE.
Old 23rd December 2012
  #19
Just FYI everyone... I had 3 8-channel, 88.2k, 24-bit interfaces connected through the 2 Firewire ports (same buss though) on my 2.0 GHz iMac. All 24 tracks record and playback without skipping a beat. The full 24 tracks have only been utilized a couple times when I'm actually "testing" the system. But work perfectly, like I said. In practice, at most I've had 20 tracks when doing a full band, usually less (usually it's a few scratch channels recording the whole band, with many overdubs). I honestly can't foresee ever using more than 24 tracks at the same time, except for maybe recording a full orchestra with discrete mics on all instruments. But that application isn't on my menu, so it's probably never going to happen. Point is... 24 channels of 24-bit/88.2k recording (with 4 mono channels of monitoring/playback) is possible through FW400. Used a MOTU 828 mkII, a Presonus FP10, and a Focusrite Saffire 40 Pro. Juggling drivers was so tricky that I gave up on the Saffire 40 through FW, and have a Presonus Firestudio Lightpipe connected through Firewire now. The Firestudio LP, the FP10 and the 828 mkII drivers all play together nicely. The Saffire 40 and the new Mackie Onyx Blackbird are going through the ADAT in/outs on the Firestudio Lightpipe. So... yes you're reading that right... I now have THIRTY-TWO channels usable at any time, with SIX stereo headphone channels (don't know if they all work together as I don't have enough mics to test.) through FW400. Seriously doubt I'll ever use them all, but I have a number of analog mic pre's going through the John Bonnell "upgraded" 828 inputs, all-in-all giving me a variety of pre-amps to apply to different situations.
Old 11th October 2017
  #20
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I know this is 5 years later, and technology has progressed significantly since this post, however, this info was exactly what I was looking for and still relevant, I think, for digital audio concepts. I'm looking at using two LS56's and an 828mkii, but my application is really more for summing. I don't need a whole bunch of inputs [maybe 12 or 16 simultaneous at the most], but I do need as many outputs as I can get as the console I'm using for summing facilitates 48 channels. So the dream is to daisychain the LS56's and then run the 828 directly to the firewire buss. Hopefully I can get a solid 30 channels out and running stable. Thanks guys!
Old 11th October 2017
  #21
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hello. i run 48 discrete audio outputs via firewire to my motu 2408s, then into my 2 Alesis hd24 hard disk recorders. so when mixing i basically run 48 tracks into my analog console. its a DDA amr 24 and has 56 channels on mix down. hope that helps. buddha
Old 11th October 2017
  #22
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Quote:
Originally Posted by djryry View Post
I know this is 5 years later, and technology has progressed significantly since this post, however, this info was exactly what I was looking for and still relevant, I think, for digital audio concepts. I'm looking at using two LS56's and an 828mkii, but my application is really more for summing. I don't need a whole bunch of inputs [maybe 12 or 16 simultaneous at the most], but I do need as many outputs as I can get as the console I'm using for summing facilitates 48 channels. So the dream is to daisychain the LS56's and then run the 828 directly to the firewire buss. Hopefully I can get a solid 30 channels out and running stable. Thanks guys!
I had three LS56 interfaces concurrently, but the device drivers written for them by Focusrite only allow *one* LS56 to be connected to the computer via the firewire at a time.

The best you can do is attach one LS56 to the computer via firewire, and add a Saffire PRO 40 which is supported to work concurrently via firewire with the LS56. If you add your ADAT-connected LS56 for a few more channels, and a couple more ADAT devices, it think you'll make your I/O count objective.

EDIT: The Saffire Pro 40 is not officially supported to work with an LS56 in Dual Unit Mode, but it does apparently work according to a few appends in the AVID DUC forum. http://duc.avid.com/archive/index.php/t-302917.html

A member of the Focusrite tech team replied that it's very possible to have glitches and click issues when using combinations that are outside of the green cells of the chart on page-2 in the Saffire Dual Unit Guide PDF document. BTW it's 48khz max supported.

https://us.focusrite.com/downloads?p...Saffire+PRO+14

Last edited by MediaGary; 12th October 2017 at 12:56 PM.. Reason: Added links and corrected model nbr
Old 12th October 2017
  #23
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Quote:
Originally Posted by BIG BUDDHA View Post
hello. i run 48 discrete audio outputs via firewire to my motu 2408s, then into my 2 Alesis hd24 hard disk recorders. so when mixing i basically run 48 tracks into my analog console. its a DDA amr 24 and has 56 channels on mix down. hope that helps. buddha
Thanks! Super helpful! And is that at 96k?
Old 12th October 2017
  #24
Here for the gear
Quote:
Originally Posted by MediaGary View Post
I had three LS56 interfaces concurrently, but the device drivers written for them by Focusrite only allow *one* LS56 to be connected to the computer via the firewire at a time.

The best you can do is attach one LS56 to the computer via firewire, and add a Saffire PRO 40 which is supported to work concurrently via firewire with the LS56. If you add your ADAT-connected LS56 for a few more channels, and a couple more ADAT devices, it think you'll make your I/O count objective.
Really intriguing. Was that even with "Dual Unit Mode" enabled? Obviously it would only account for two units, but it'd definitely be a start of sorts. I'm picking up my second one either later today or Friday. I'll try to check back to let you all know how it goes.

The dream is that the two LS56s work well in the famed "Dual Unit Mode", the Focusrite drivers and the MOTU drivers for the 828mkii play nice together so I can hopefully realize the combined 30-34 analog outputs for mixing/summing through my Soundcraft 6000. It'll handle about 72 channels of input, but the full use of that will be when I get my two Orion32+s. For now, the 30+ potential channels I can get from those three units will have to do! Lol!

We'll see...
Old 12th October 2017
  #25
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Actually the Dual Unit Mode PDF says only a Saffire PRO 24 and lesser (not the PRO 40) can be used with the LS56. It confirmed that two LS56's cannot be used in Dual Unit Mode.
I'm typing with thumbs now, but will edit with a link to PDF, and correct my original append.
Old 12th October 2017
  #26
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Some relevant information from Focusrite: Avid Pro Audio Community - View Single Post - Focusrite: Saffire Pro 40 Firewire, or Scarlett 18-20 usb2 on Mac?

Quote:
Remember though that this is all very theoretical. If you calculate out the theoretical maximum bandwidth of Firewire it will tell you you can send something crazy like 176 channels. This does not actually happen in practice.

Still you will see that we will not make a unit that cannot support it's own Channel Count fully.

Note that the Saffire Interfaces have a Dual Unit Mode, where the USB devices do not. So while the 18i20 and Pro 40 have the same Channel Count you can connect two Pro 40s together with a firewire cable and use their full channel counts, 40in 40 out.

However you cannot connect two LS56s or an LS56 and Pro 40 with official support.

Also Dual Unit Mode is only supported up to 48k.

Note that "not supported" doesn't mean I have not tried this and had minimal success. I have a Pro 40 and LS56 hooked up right now on my desk in 88.2 and they are passing audio. However as things reach the bandwidth maximum I will likely notice crackles, pops, or drop outs on the firewire bus. This will probably be a lot worse if I am also sending Outputs, rather than just using inputs, due to the bi-directional transfer, and use of much more bandwidth. Remember also that high Sample Rates are doubling your bandwidth, so going from 48k to 88.2 is HUGE difference in transfer.

This is why there is a "Supported up to two Pro 40s at 48k." We will make sure the units can actually 100% perform whatever max channel count we say they have. Above that we cannot support it or say it will actually function properly.

So rest assured, if you see it on the box it works for sure!
Old 12th October 2017
  #27
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My experience with chaining and driver aggregation of various Firewire interfaces is less than stellar to say.. depending on chipset drivers etc. For example two RME
Firefaces were fine, but Saffires (not LS56's.. although normally fine) were bit problematic and not really stable that way.

I'd rather suggest to set first LS56 interface as a master one, use it from DAW and set two others to standalone mode and connected via ADAT (both second LS56 and MOTU 828).
That way, everything would be manageable from one MixControl and 24 channels accessible via single standard ASIO driver.

Of course full channel count with 16 ADAT I/Os will be limited to rates up to 48k, but I somewhat assume, that's likely not a problem, if you starting with recycling of "old" interfaces.

Couple of relevant links..
https://support.focusrite.com/hc/en-...eamps-via-ADAT
https://support.focusrite.com/hc/en-...andalone-Mode-
MOTU.com - Using a MOTU Audio Interface as a Standalone A/D or D/A Converter

Michal
Old 12th October 2017
  #28
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Quote:
Originally Posted by BIG BUDDHA View Post
hello. i run 48 discrete audio outputs via firewire to my motu 2408s, then into my 2 Alesis hd24 hard disk recorders. so when mixing i basically run 48 tracks into my analog console. its a DDA amr 24 and has 56 channels on mix down. hope that helps. buddha
2408s connect to a PCI(e) card via a Firewire CABLE carrying the AUDIOWIRE protocol. For all I know, it's pure Firewire with a MOTU Stamp of Approval on it, but THEY are careful to differentiate it as incompatible with Firewire.
Old 12th October 2017
  #29
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JayTee4303's Avatar
Quote:
Originally Posted by djryry View Post
I know this is 5 years later, and technology has progressed significantly since this post, however, this info was exactly what I was looking for and still relevant, I think, for digital audio concepts. I'm looking at using two LS56's and an 828mkii, but my application is really more for summing. I don't need a whole bunch of inputs [maybe 12 or 16 simultaneous at the most], but I do need as many outputs as I can get as the console I'm using for summing facilitates 48 channels. So the dream is to daisychain the LS56's and then run the 828 directly to the firewire buss. Hopefully I can get a solid 30 channels out and running stable. Thanks guys!
Keep any Toslink cables as short as possible, Wordclock MAY lighten the load there, and pipe a couple minutes of 2 kilohertz sine wave out your pipes, simul, for an audible checkon performance. Rice crispies tend to stand out on a 2k tone.
Old 14th October 2017
  #30
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just replying to the next question regarding sample rate .

i run both my HD24s at 48k as this is the default sample rate when running either tape based Adats or the Alesis HD24 hard disk recorders, when used in conjunction with an Alesis BRC (big remote control).

if you run without a BRC you can choose sample rate option of either 44.1 or 48k, selectable from the recorders themselves.

regarding the other comments. yes the motu card which plugs into the mac pro is a pic-e card , and the cables themselves motu call an audio wire.

audio wire cables are basically firewire cables, the difference being that but the metal prongs are slightly longer on firewire cables.

anyway most consider it a firewire system and it handles 48 audio inputs and/or 48 outputs at 48k no problems at all.

been running it in the studio all day for many many years now.

i do hope this information helps you. good luck Buddha
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