DP CPU usage with multi-timbral instruments

[magicd]

Here's a tip for getting the most out of virtual instruments running in DP8.

Because DP8 uses 64 bit addressing and can access all the available RAM in your computer, it is possible to load large amounts of sample based virtual instruments into a DP session.

DP can take advantage of multiple CPU cores. To get maximum efficiency with virtual instruments, it's a good idea to spread the processing load of those instruments among the available cores. Each fader strip in DP can be seen as a separate processing thread by the OS. That means that a single multi-timbral instrument plug-in on an instrument track in DP will be limited to a single CPU core. However, if multiple instantiations of the instrument plug-ins are made over several instrument tracks, this will allow the OS to use multiple cores to handle those separate instruments.

So instead of running 16 sounds inside a single multi-timbral virtual instrument, try spreading those sounds out over three or four instantiations of the multi-timbral VI. You may see a significant increase in CPU efficiency.

Dave

[MIDI Life Crisis]

Excellent! Thanks.

[mikehalloran]

Nice tip. Thanks!

[MIDI Life Crisis]

Does it matter if it is in a v-rack? Does using a v-rack (or not) make any difference in terms of CPU performance? Obviously in multi-chunk projects using the same instruments, v-racks greatly increases the efficiency when switching between chunks (some people prefer a single project per cue, which seems a little redundant to me), but I guess my question is: do we get the same distribution to the multi-cores using a v-rack?

[magicd]

The efficiency of using a V-Rack is that you don't have to wait when switching chunks.

V-Rack faders work the same as sequence faders. Spread the load!

Dave

[MIDI Life Crisis]

[emulatorloo]

Great stuff! Thanks!

[MIDI Life Crisis]

Well now I use V-Racks with large instruments in their own VI. Makes sense. It doesn't seem to help latency when the buffer is at 1024, but that's fine. I'm sure it will help with lower settings.

Speaking of which, perhaps I'm just a little slow to realize this, but if you want to hear the latency of your settings, use a keyboard with the ability to turn local playback on/off. Turn local on while sending the signal to the VI. The delay you hear is the latency. Duh!

I hear Shooshie has a bridge for sale in my hometown?

[Kubi]

Admins, mods, if it's not already there, I think this should go in the DP tips thread...

[MIDI Life Crisis]

I posted it already. Things running VERY smoothly right now. MachFine 3 seems to be loosing track of what instruments are loaded but that might have started prior to the switch. I have to troubleshoot that a little more.

[Shooshie]

Admins, mods, if it's not already there, I think this should go in the DP tips thread...

Done! (in the Tips Sheet itself)

[williemyers]

hey guys, I'd like to drag this thread back up again for a moment?

Dave's tip is very useful (and always welcome) but, in ways, opens even more questions that sort of hang out there.
In a similiar thread, KGDrum had asked specifically if Dave's tips applied to Kontakt, as well as to MachFive. Mike responded with a link that answered the question but, again, only as it applied to MachFive. As I'm starting to get frequent DP8/K5 crashes, I'd be one of those who (somewhat desperatly) needs to know more about the multi-core relationship between DP & Kontakt5.
I've found that going in to the settings of a Kontakt instance in DP8, and attempting to turn on, or raise, the multi-core setting in Kontakt5 will cause K5 to throw up a warning msg., something to the effect "Using multicore support in K5, when K5 is being used in a DAW that supports multicore, can cause problems..." or words to that effect. So, the question still hangs out there....when using K5 instances in DP8, is it a good idea to have K5 multicore support on or off? Or does it make any difference?

many thanks

[kgdrum]

Hi Willi I responded in the other thread,since you're also asking here I'll paste my answer here as well.

The reason I've asked these questions primarily is because I keep getting told different answers depending on if I talk to people at MOTU tech support,NI tech support or by other users on forums,I can tell you I really don't have a clue what's the best approach,
lol
NI told me use multicore support,leave on KMS and designate 3 cores on a Quad,5 cores on a Sixer,7 cores on a Octo,etc.....
I think I was told to ignore the message & if I wasn't told that I ignore the message anyway.
I only see it when I change the setting in DP.
I've never seen an actual problem,so unless my Mac starts crashing I leave it as it is.
I think the worst that can happen is a crash or higher CPU demands but you can just change back if it doesn't work as well with the setting changes.
I have KMS off and 3 core setting for my Quad.
NI told me to leave KMS on,I don't because I expect DP 64bit operation to make KMS unnecessary.
Will I see better performance or stability if I change to 4 core setting or turn on KMS?
I really don't know if I've ever really noticed a big enough difference,either way with these different settings.
Many people say leave KMS off,forget the core stuff because DP does it.
I have KMS off & I have 3 core multicore setting for my Quad.
I'm not a "heavy" user,my demands as they are ,I rarely notice a difference.
I don't do massive tracks ,film scores,Orchestral or have slave PC's running farms of samples with VEP etc...
It would be great to get a definitive answer but I expect to continue getting different answers depending on who we pose the question to.
Maybe call NI tech support would give you an answer,I'm curious to hear what they tell you......

[Frodo]

It would be great to get a definitive answer but I expect to continue getting different answers depending on who we pose the question to.

This is far from a definitive answer, but we should remember that NI's hosts can still run in standalone mode, by virtue of which we'd still want to have some control over CPU usage options.

Now that 64-bit world is here in DP, the question remains what's necessary where CPU usage/assignments go in contrast to what's optimal in 32-bit world-- or in contrast to plugin vs standalone world.

It's a tough kettle of nutty fish to crack.

[Killahurts]

FWIW, I consolidated a large template the other day, from being spread over two computers, to the main machine only.. this, just to see if the computer could even do it. I had about 30 instances of K5, 2 or 3 MachV's, some Omnispheres, Stylus, and some other VI's. I was amazed to find that the computer handled it perfectly. No lags or beach balls- dare I say DP was snappy?

I have KMS off. With 64 bit DP, I can't see how the KMS could do anything but create a memory mess. I've also left the other K5 settings, like cores, etc., where they are by default (off?).

I've always used Magic Dave's technique of having more VI instances, rather than to try to port a single instance to multiple outs. Not because I knew it's better, I didn't. But this thread is great confirmation for me..