CPU optimisation help request

[gavspav]

I've made a Live Set for an installation which receives data from Osculator on four separate tracks, processes it in a Max for Live object on each track and then passes it to an instrument rack which contains about 15 different drum racks. Only one drum rack per track is active at a time, according to a chain selector clip envelope in a track.

Each drum rack responds to 7 midi notes, about half of which contain a simpler or sampler, the rest an ableton instrument.
There are also some effects.

Each different scene activates a different set of 4 drum racks but although there are only 4 racks active at one time the cpu usage is around 50%. I am getting dropouts, even when there is no osc data coming in. If I delete the tracks with the nested racks, the problem goes away.

I have read about problems with nested racks.

I am using a 20011 i7 mbp, 8GB Ram with Lion and a Komplete Audio 6 interface, buffer set at 512

Has anyone had any issues like this - what's the best way around it? Does Live use CPU cycles for inactive instrument chains/inactive instances of simpler/sampler.

Any tips on how best to reorganize my set?

Thanks.

[gavspav]

Well I cleared a load of stuff off my laptop, followed a bunch of optimisation tips, turned off airport, indexing etc but none of it made any difference.

I then realised that turning off my unused nested drum racks saved a lot of cpu power so I hacked a m4l device to turn all racks off except for the one in the selected chain.

I expected the chain selector would do this but it doesn't seem to in this set anyway.

My CPU has gone from 55% to a steady 16%

[Tone Deft]

nice work.

I believe the reason the chain selector won't do it is because Live has to be ready to play the racks not selected by the chain instantly, so it can't just turn them off.

[Razzkazz]

It says in the manual "Racks already conserve CPU in inactive chains". In practice, this is not the case. There is no difference in CPU usage when chains are made inactive. Chains can be assigned to different zones and you only have one chain active, or even a "Dry" empty chain, this makes no difference in CPU usage. The only way to free up the CPU is to "add device on/off automation using macro mapping"