128 samples latency or less w/MBP - what interface?

slirak · Post by **slirak** » Sat Nov 08, 2008 8:59 pm

Hi,

I'm gonna get myself an MBP (either the old 2.5GHz model or the new 2.4 one). I'd like a firewire card that will pass Live's CPU test at 80% (=max) w/o crackle'n'pops at a latency setting of 128 samples or preferably less. I'll also need at least one high impedance instrument input and one true 48 v phantom power mic input with decent mic pre. Small physical foot print preferred.

Any suggestions?

Thanks
/Jonas

Landwhale · Post by **Landwhale** » Sat Nov 08, 2008 9:19 pm

Not sure if it is too big for your footprint requirements, but I really like my Motu Ultralite.

I have a 2.4ghz C2D Macbook Pro w/ 4gb of ram, running Live 6.0.10 on Leopard.

Using the Ultralite, running Live's built-in CPU test at 44.1khz at 80%, I don't get any crackles, pops or other glitches AT ALL with 128 samples latency. I get SOME crackles and pops at 96 samples, but not bad.

At 64 samples, again using the built-in CPU test @ 44.1khz, I don't get any crackels until 73%.

For what it's worth, I normally work at 44.1khz with a latency setting of 64 samples, for both tracking and mixing. With the exception of certain sessions with lots of fine audio edits and/or a ridiculous amount of plug-ins, I don't have any problems with audio glitches. If I do, and I'm mixing, I just bump up to 128 or 256 and that takes care of any rice crispies.

dru · Post by **dru** » Sun Nov 09, 2008 12:36 am

I run my Firebox at 128 samples, works fine.

leedsquietman · Post by **leedsquietman** » Sun Nov 09, 2008 12:54 am

it's never that simple. If you add lots of tracks and lots of intensive plugins, then you will always need a bigger buffer.

Landwhale · Post by **Landwhale** » Sun Nov 09, 2008 2:11 am

leedsquietman definitely has a point, but as far as my setup goes, I can run 20-30 tracks with plenty of plugs with no problems. Granted, I'm not running shitloads of CPU heavy plug-ins ALL the time, so obvioulsy results would be different if that were the case. Also of note, I'm still running Live 6, so I'm not sure how 7 would compare as far as CPU is concerned.

But to answer your question as it was originally asked, regarding using the built-in CPU test, the Motu meets your requirements. It is also very, very stable.

Do you need 128 samples or less all the time, regardless of whether you're tracking or mixing? What kind of plug-ins are you using?

alltomorrowsparties · Post by **alltomorrowsparties** » Sun Nov 09, 2008 3:09 am

any of the tc konnekt stuff.....i ran a 16 track logic project as a test the other day with about 10 space designers (convolution reverbs) and loads of compresors/eqs at 32samples per buffer....sound is amazing also

Kodama · Post by **Kodama** » Sun Nov 09, 2008 4:53 am

I reliably get 160 samples @ 44 khz at high (75%) cpu usage w my Ultralite.

I would be suspicious of thinking that a Firewire interface could do better than that under the same circumstances, you would likely need an expresscard interface to do much lower.

timothyallan · Post by **timothyallan** » Sun Nov 09, 2008 5:30 am

That's nuts, I usually have to keep it at 512-1024 with my Motu 828 Mkii when I start pushing the track/au count on my MBP 2.4ghz. Same drivers as the ultralight too, must be a hardware thing.

Kodama · Post by **Kodama** » Sun Nov 09, 2008 6:01 am

Well I'm running @ 48khz, prolly ur running @ 96khz - which takes much more cpu?

timothyallan · Post by **timothyallan** » Sun Nov 09, 2008 6:03 am

Umm nope? I run 44kHz as I don't do much video work.

Kodama · Post by **Kodama** » Sun Nov 09, 2008 8:27 am

Hrmmm... That's odd, is your MKII USB?

timothyallan · Post by **timothyallan** » Sun Nov 09, 2008 8:32 am

Nope it's FW. It was the same from 10.4.11 to 10.5.5 as well...

slirak · Post by **slirak** » Sun Nov 09, 2008 8:43 am

This is all very interesting - and a bit confusing.

I did choose to ask about Live's perfomance test because as Leedsquietman points out, how many real world tracks you'll get will vary greatly depending on your f/x and instruments.

However, I should also have asked: at what CPU strain (as reported by Live) do you experience crackles - in actual projects, not the test?

I often get crackles at a mere 40 - 45% in real world projects, even if I pass the CPU test at 80%.

/Jonas
Current equipment:
C2D@2GHz, 2GB RAM, 7200 rpm drive (PC running XP SP3), Emu 1616m PCMCIA soundcard

Kodama · Post by **Kodama** » Sun Nov 09, 2008 6:38 pm

That means you need to bump up your latency.

Too low of latency = crackles @ cpu % that is unacceptable to you

Too high of sample rate = CPU % is too high

You have to find the right balance.

Using my Ultralite Mk III at ~70% CPU, I can get 160 samples very stable, with no crackles, even while audio recording and playing midi controllers at the same time.

Nothing is as simple as a benchmark, it takes testing under your circumstances to see how an interface works for you.
The difference in I/O milliseconds between 160 and 128 @ 48 khz = 7.15 Vs 8.48.

If I crank the Motu up to 192khz, I can get like 2.67ms total I/O @ up to 50% cpu, but my CPU is hurting more due to everything being rendered @ 192k.

Of course, many dj types could do fine with that

slirak · Post by **slirak** » Sun Nov 09, 2008 7:26 pm

Kodama wrote:That means you need to bump up your latency.

No. Unfortunately this means I need to get another sound card. And a better computer.

Thing is, I use an e-drum kit to trigger Session Drums and when I play the drums, I'm very "latency-sensitive". I also record guitar and bass and like to monitor them "wet" through Amplitube 2 and I'm quite picky (sorry 'bout the bad pun!) when I record guitar too. To add insult to injury, Amplitube is one serious CPU hog.

There are several workarounds of course and I probably use them all. But I'd rather not have to and since I'm switching to Mac I need a new card anyway (the 1616m uses PCMCIA).

Kodama wrote: Nothing is as simple as a benchmark, it takes testing under your circumstances to see how an interface works for you.

I'm well aware how my current sound card performs.

I'm trying to get advice on how other sound cards perform and since I don't have any other sound cards around to benchmark I'm asking you folks...

Now I know that USB is considered a big no-no, but that rep is mainly earned from 1.1 cards. I've read some pretty nice stuff about the EMU USB 2.0 cards though - anyone using them?

I'm also a bit curious about the ESI Duafire which claims latency down to 1.5 ms. Anyone?

(I guess I should stop whining and get myself an eight core Mac Pro and some Apogee Rosetta stuff!!! But I didn't win the lottery this weekend either and anyway, I like my computers portable.)