ableton users - external sync cpu usage

when i toggle "ext" (external sync) to slave ableton to my mpc i get a 5-6% spike in cpu usage. if i let ableton run itself it invariably decreases. from what i can gather his is and has always been an issue with ableton. anybody else care to confirm/deny. i'm on the latest version of live 8.

- jim

The cpu usage does jump around, im on 9. Nothing I worry about.

What are the benefits of having the 4ooo as the master?

i normally don't worry with it either but i'm able to run a very small buffer size and in the case of larger live sets that 5-6% can mean the difference between running smoothly and popping/crackling.

as far as benefits, i just like having the transport control on the mpc. i prefer not to have to click on the computer to start/stop a track...just personal preference. i'm gonna spend the morning seeing if i can address this.

what's your method?

- jim

dustymaestro wrote:The cpu usage does jump around, im on 9. Nothing I worry about.

What are the benefits of having the 4ooo as the master?

Outside of Audio/MIDI interfaces costing $800-$2000USD or an Innerclock MIDI system, the 4k will win in MIDI timing and lower MIDI drift ratings. In addition to transport, ease of running the session that Jim mentioned. The 4k rates ridiculously high in head to head showdowns against most any MIDI timing solution.

And yeah the little bit of extra CPU overheard in Live with Ext. sync is a long time thing in my experience.

What audio interface is Ableton running off of jimfowler?

using ableton as master gives me start/stop via the space bar but i use all the transport controls regularly, so having the mpc be boss is mo betta.

i played around with clock versus time code and syncing ableton to MTC did not result in the same cpu spike...unfortunately, MTC doesn't do song position pointers.

from ableton's manual: "If the master sequencer can generate MIDI Time Code (MTC), this would be the recommended option since MTC has a better resolution. However, as MIDI Time Code does not transmit any tempo information, the BPM will have to be set manually in Live to match the BPM of the master sequencer."

interface is a pair of echo audiofire 12 unit. once lynx releases their L-slot thunderbolt kit i'll move up to an aurora 16.

jimfowler wrote:using ableton as master gives me start/stop via the space bar but i use all the transport controls regularly, so having the mpc be boss is mo betta.

If you send MMC from the MPC3000 transport controls, to the Ableton transport controls, with Ableton as the MIDI Clock or MTC master, then MPC can still be mo betta transport boss while Ableton can be timing boss.

jimfowler wrote:i played around with clock versus time code and syncing ableton to MTC did not result in the same cpu spike...

I synced Ableton 8 to an MPC2000XL recently, and noticed the Ableton tempo display jumping around constantly.

I would guess that as Ableton is constantly readjusting it's internal tempo to match the incoming MIDI Clock tempo, that the CPU spike might be the internal Ableton audio engine readjusting it's audio playback constantly to match the minute constant incoming tempo changes.

jimfowler wrote:unfortunately, MTC doesn't do song position pointers.

You don't need Song Position Pointers with MTC, MTC has more accurate positioning built-in to it's timing system.

What do you think you need Song Position Pointers for?

I only use start, stop and record when syncing. Im using midi clock, using both seq. at the same time. Live is the master. No complaints, its running smooth.

"What do you think you need Song Position Pointers for?"

sorry, misspoke - i was confusing transport control updates with spp. i had the whole thing mixed up. to be frank, i've never had to mess around with anything other than midi clock until now so some of the terminology is new to me.

"I synced Ableton 8 to an MPC2000XL recently, and noticed the Ableton tempo display jumping around constantly.

I would guess that as Ableton is constantly readjusting it's internal tempo to match the incoming MIDI Clock tempo, that the CPU spike might be the internal Ableton audio engine readjusting it's audio playback constantly to match the minute constant incoming tempo changes."

yep, it's constantly moving around. and perhaps you're right about the cpu spike relating to the audio engine constantly adjusting. i get the same initial spike when ableton first gets MTC but then it settles.

so far MTC is working way better. thanks for the tips.

MPC --(mtc)--> Live

this works way better. i still get periodic cpu spikes (and corresponding crackling) so it's not bulletproof...but still markedly better.

Live --(clock)--> MPC (w/ mmc coming from mpc)

no go. once the transport is running, live will respond to "stop" command from mpc transport but hitting "play" on the mpc gets me a "Waiting for MIDI 'Play'" message from the mpc. maybe it's some weird handshake thing going on...almost seems like it's a case of neither machine can start without the other one. from everything i can gather, Live does NOT respond to mmc. you can map a control surface buttons to Live's transport OR you can have Live follow via sync but not via mmc solely.

why oh why can't live just follow clock like a good boy.

"If you send MMC from the MPC3000 transport controls, to the Ableton transport controls, with Ableton as the MIDI Clock or MTC master, then MPC can still be mo betta transport boss while Ableton can be timing boss."

you got this to work on a 3K? fwiw, live can only send out MIDI CLOCK. no mtc, no mmc. it can respond to clock or mtc. no mention of mmc in the manual...the transport controls are midi-mappable but mpc transport does not show up as usable midi data in live.

The Live systems I have to play with are at work, so I might have mixed up what I was doing with them, when posting here.

Will see if I can grab a laptop and MIDI interface on my way past work next time, to bring it home and give it a go.

if it's not too much hassle it would be great to have some confirmation/denial.

Can you list the sync MTC/MMC settings you are trying to use?

MPC settings:

under "MPC Sync Out" (misc --> sync)

MIDI time code: MIDI OUT-B
Send MMC (Midi Machine Control): MIDI OUT-B

LIVE settings:

under "Preferences", "MIDI Sync" tab

Input: Audiofire12 Sync ON
Sync Type: MIDI Timeclock
MTC Framerate: 30 fps

however, in the above setup MMC is redundant. start/stop/etc. is all sent via MTC (since Live is slave, it's just following along). toggling MMC on/off makes no difference.

setting the machines up with Live as Master is as follows:

MPC

under "Sync In"

Mode: MIDI CLOCK
Sync in:MIDI IN-II

under "Sync Out"

Send MMC: MIDI OUT-B

LIVE

Output: Audiofire12 Sync ON

the above send midi clock out of ableton but ableton does not respond to mmc commands. when i hit "play" on the MPC it's not getting the message from ableton.

i hope this all makes sense. thanks again for your input. i've emailed ableton...we'll see how long it takes for a response. so far, the best (but least preferable) method is to let Live be the master.

I use it mostly this way.

heyho,

i was experiencing the spikes in live (9.0) too but not worrying since i like the MPC's master clock (timings)
but
when i record audio (voice) in Live in a song and afterwards wants to bounce the whole thing i need to set the master clock in Live to internal, since bouncing doesn't start external
and
then i get rather huge differences in timings (since int. clock is 'stable') and MPC's is not (or not so stable in Live as during recording with master clock from MPC)
have u issues with this?
jay