Logic vs. DP -- something just occurred to me

[Shooshie]

For a long time we've compared Logic vs. DP in terms of how many instruments they would load, and how fast they'd run them. Something just occurred to me. In Logic, each track appears to load an instrument. In fact, if you are loading strings or guitars, or any other instrument for which you're liable to have multiple lines of music playing -- several players on similar instruments -- then Logic isn't likely loading a new instrument for each, but merely routing the track to the instrument loaded on the first such track.

Therefore, if you have:

Four violins
Three guitars
eight drum tracks
two pianos
two basses
3 tracks of the same synth pad

Then you have 6 instruments loaded, not 22, as you would get if you counted tracks.

When people tell us how many instruments Logic loaded, are they in reality telling us how many instrumental tracks? I noticed that someone while ago was afraid that adding a bunch of tracks from Polar would up his CPU hit. That logic would come from Logic, not DP. In DP, one instrument, whether in V-Racks or the Sequence, would handle all the tracks fed to it, and adding notes of polyphony generally does not affect the CPU too adversely. Sure, several dozen would clog up that instrument, but it's more the limitations of the instrument, not the CPU so much. Of course, if you don't have a fast hard drive, playing a lot of Rachmaninoff 10-fingered chords on rapid succession on Ivory will most definitely outpace the drive's ability to stream the data, but the computer will handle it fine.

I dunno… just thinking out loud. For a while it seemed like Apple was somehow cheating physics to run that many instruments at once with no discernable CPU hit. Especially if they were all sampled. Now the difference doesn't seem so great, but I still wonder if the reports were accurate. Maybe some users reports failed to distinguish between samples and synths. Well, I'm just sayin'…

Shooshie

[Frodo]

I've had to come to accept that virtual reality doesn't parallel reality so neatly.

At the same time, it's easier to compare what Logic does with loading VIs with how romplers work (drawing upon already loaded data to save memory) than it is to compare it to DP's point-by-point VI loading process.

The thing is that human beings (and a certain contingency of hobbits) think in terms of point-by-point: Add 'x' amount of RAM and you should be able to load 'x' amount of instrument data. But then there's Virtual Memory which I've seen manage twice as much data as a given Mac has in installed RAM. How that really works is one of those Cupertino secrets.

I've never had a problem with MAS instruments in DP or Logic's own instruments in Logic. I'm just wondering if you are comparing Audio Units to Audio Units in each-- if so, which ones?

[Shooshie]

Yeah, what was I thinking? Of course, anyone in their right mind would compare similar to similar. So AU to AU it is. Never mind… everyone can move on; nothing to see here.

Shoosh

[michkhol]

But then there's Virtual Memory which I've seen manage twice as much data as a given Mac has in installed RAM. How that really works is one of those Cupertino secrets.

Virtual memory technology has been known since multitasking was invented, in my memory it goes back to PDP-11 and its XM kernel. The trick is simple: the program does not have control over the memory it requested, the operating system decides how exactly this request is fulfilled. The program may see its memory as a contiguous chunk of bytes, in fact it may be scattered around RAM and disk: http://en.wikipedia.org/wiki/Virtual_memory

As for Logic vs DP, Logic has had consistently higher VI count (not track count) then DP for me. Which does not help me at all, because DP seems to be the only DAW that fully supports time signatures.

[misterlast]

Shooshie wrote:
"I noticed that someone while ago was afraid that adding a bunch of tracks from Polar would up his CPU hit."

It looks like you might be referring to my posts on Polar.
I think you've got the virtual instruments vs tracks issue sorted out and I don't think I should try to get into virtual memory, but I'm wondering about your Polar position. In my experience printing Polar sessions create new audio tracks and have nothing to do with virtual instruments or MIDI tracks.

And that adding many, many audio tracks, in addition to multiple instances of Kontakt or even DP MAS instrument with multiple MIDI tracks fed to each Kontakt VI has the potential to spike CPU (though this is probably a moot point, since I've had no CPU issues with a 7200rpm hard drive 2.6Ghz Macbook Pro and 6gb Ram; those cpu issues were with a powerbook g4 with a slower hard drive).

My issues were in just trying to more efficiently manage the printing of Polar passes during and after a polar session.
Thanks

[Michael Canavan]

@Shooshie,
Logic doesn't use the same instrument for multiple tracks in some sort of cpu saving feat. The best way I've heard it explained is that Logic unlike Cubase, DP, and Live for example, arms, or polls only tracks that are armed (ie are record enabled), this is one of the ways that Logic conserves CPU cycles, and probably why Mainstage is a CPU pig compared to Logic.

Logic has ALWAYS been the the CPU king, the PC version was the leanest DAW on Windows before Apple trashed that version, so it's not Apple giving the Logic team an unfair advantage etc. Talking about the EXS24 sampler in particular though, that's just one seriously lean sampler, a real dinosaur feature wise, but for some libraries it's brutally efficient.

Setting up Kontakt for instance to have multi outs is MUCH easier in DP, and the results should be similar I would guess.

[Shooshie]

Thanks, Michael. That's basically the position I'd come to believe, and your posts have confirmed that. (I retracted my earlier position above) And now I do remember hearing that Logic had some means of arming and disarming instruments, but I have trouble imagining it since it would mean loading and dumping samples. But I don't have to know how it works to believe that it works. And DP has been awfully efficient for a number of versions now, so I believe that in some cases the difference is probably not a lot.

Shooshie

[twistedtom]

I do not see having any issues with cpu spikes unless you are running one hell of a lot of VI's and effects at once shoeshie.

[Shooshie]

True, true. It's been wonderful for me. I haven't been attempting to run a full orchestra on it, but I'm getting 12 to 15 discreet instruments -- many of which are from Vienna's huge libraries -- to run without ever getting in the upper range of the CPU meter.

There is ONE issue that bugs me with DP. There is something that peaks the meter ever so often, like a spike, and I have NEVER been able to track it down. It happens in the most humble of sequences with no audio, and it happens with jam-packed audio sequences. Makes no difference what it is. It's like maybe there's a memory cleanup going on or some other background feature. It's not on my Mac -- there's no apparent spike like that going on in the Activity Monitor with DP resting. But while playing, that CPU spike goes through there.

The result is null. It doesn't seem to change anything except the status of the peak meter. That's why I don't normally worry about it, but it just bugs me not to know what it is.

Shooshie

[Frodo]

True, true. It's been wonderful for me. I haven't been attempting to run a full orchestra on it, but I'm getting 12 to 15 discreet instruments -- many of which are from Vienna's huge libraries -- to run without ever getting in the upper range of the CPU meter.

There is ONE issue that bugs me with DP. There is something that peaks the meter ever so often, like a spike, and I have NEVER been able to track it down. It happens in the most humble of sequences with no audio, and it happens with jam-packed audio sequences. Makes no difference what it is. It's like maybe there's a memory cleanup going on or some other background feature. It's not on my Mac -- there's no apparent spike like that going on in the Activity Monitor with DP resting. But while playing, that CPU spike goes through there.

The result is null. It doesn't seem to change anything except the status of the peak meter. That's why I don't normally worry about it, but it just bugs me not to know what it is.

Shooshie

I see that often-- more in 5.13 than 7.x, though. What you said about "memory cleanup" resonates--- I can't necessarily track it down in Activity Monitor, except that I do see bursts of data from time to time. Perhaps it's just a refresh of Virtual Memory?

Also, some plugins I tried to install required Rosetta in Snow Leopard. This is, in effect, another "wrapper" of sorts. So, with one additional layer of data conversion on top of all that goes on between MAS and Core Audio, the occasional CPU cough doesn't surprise me.

I also agree-- it's not a big deal, but it does make one wonder just what happens when the Audio Performance readout suddenly hangs red when the overall CPU level hovers on the low side even with the smallest projects. As long as the CPU doesn't linger near its peak, all seems to be well.