Processor spikes when playing soft synths

[chlorinedream]

Hi - I recently upgraded to the latest version of DP on my late 2013 iMac. I'm noticing something odd (at least to me)...

If I open an existing song, and add a new instrument track (Omnisphere), and start playing just the synth (the song is not playing), I'll get processor spikes and drop outs in the sound.

If I start playing the song and play the synth over the tracks, then the processor usage goes way down - less than half. No dropouts.

Is this typical behavior? Seems like playing Omnisphere without the song playing too would be less processor intensive. Is there anything I can try to prevent the dropouts when just demoing sounds? This seems like something new that just started with DP 10.1.

thanks

[chlorinedream]

Solved: It was a buffer issue. I was at 512 and changing it to 1024 removed the spikes. Didn't have issues at 512 until recently, maybe it's a sign my iMac is nearing the end.

[davang55]

I have less computer than you (iMac i5 late 2015, 16 GB) but on 9.52/10/ and 10.1 I'll get spikes when I select record or input (audio or MIDI) but no problems on playback even with virtual instruments open and audio tracks.

Some plug-ins just kill my processor (Helix NAtive for example). I make sure I have all other apps closed and I'll free up RAM/restart whatever it takes but nothing helps.

I know I need more power but it it seems out of proportion to what I'm asking of the computer. It will even spike while idling sometimes worse than on playback.

I'll try the buffer settings like you did.

Thanks

[mikehalloran]

I have less computer than you (iMac i5 late 2015, 16 GB) but on 9.52/10/ and 10.1 I'll get spikes when I select record or input (audio or MIDI) but no problems on playback even with virtual instruments open and audio tracks.

Some plug-ins just kill my processor (Helix NAtive for example). I make sure I have all other apps closed and I'll free up RAM/restart whatever it takes but nothing helps.

I know I need more power but it it seems out of proportion to what I'm asking of the computer. It will even spike while idling sometimes worse than on playback.

I'll try the buffer settings like you did.

Thanks

Yes, those are classic buffer settings issues. Increasing the buffer size also increases latency.

CueMix is one way to compensate for that if you have MOTU hardware that supports it. Another way is to limit the number of tracks that play back while overdubbing. In some studios, I will often overdub everything to rhythm guitar/bass/reduced percussion so that I can run as low a buffer as possible. When mixing, run it high since latency is no longer an issue.

[davang55]

davang55 wrote:
I have less computer than you (iMac i5 late 2015, 16 GB) but on 9.52/10/ and 10.1 I'll get spikes when I select record or input (audio or MIDI) but no problems on playback even with virtual instruments open and audio tracks.

Some plug-ins just kill my processor (Helix NAtive for example). I make sure I have all other apps closed and I'll free up RAM/restart whatever it takes but nothing helps.

I know I need more power but it it seems out of proportion to what I'm asking of the computer. It will even spike while idling sometimes worse than on playback.

I'll try the buffer settings like you did.

Thanks

Yes, those are classic buffer settings issues. Increasing the buffer size also increases latency.

CueMix is one way to compensate for that if you have MOTU hardware that supports it. Another way is to limit the number of tracks that play back while overdubbing. In some studios, I will often overdub everything to rhythm guitar/bass/reduced percussion so that I can run as low a buffer as possible. When mixing, run it high since latency is no longer an issue.
DP 10.01; 828mkII FW; MOTU MTP/AV USB with Firmware 2.0.1; MachFive 3.2.1
2017 iMac Pro 14 Core 2TB, 128GB RAM, OS 10.14.6, 2TB x2 over TB2
IK-NI-Izotope-PSP-Garritan Antares, 32Lives, LogicPro X, Finale 26.1, Encore 5.0.7, Notion 6, Overture 5, TwistedWave 1.21.9, DSP-Q 5.1.1, QuickTime Pro 7.6.6, SmartScore Pro X2 10.5.5, Toast 18
Test machine: G4-1K Dual Processor: OS 10.4.11; OS 9.2.2; DP 5.13; Encore 5.05 & 4.5.5; Toast 9.07b, legacy apps
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mikehalloran

Posts: 10693
Joined: Sun Jan 25, 2009 8:08 pm
Location: Sillie Con Valley
Primary DAW OS: MacOS

So what you're saying is monitor the live overdub you're tracking through cuemix while the signal is being recorded into DP to avoid the latency induced when I increase the buffer settings to avoid the overload condition. ??

WHen mixing with 6-8 VIs and several audio tracks it almost never overloads the processor. Weird.

Thanks so much for the help, I'm trying to catch up for many years of being away from the Tech side of things.

Jeff

[magicd]

So what you're saying is monitor the live overdub you're tracking through cuemix while the signal is being recorded into DP to avoid the latency induced when I increase the buffer settings to avoid the overload condition. ??

WHen mixing with 6-8 VIs and several audio tracks it almost never overloads the processor. Weird.

Jeff

If you are tracking a VI Cuemix is of no help. CueMix is useful for monitoring a live external signal directly. If you were tracking a real piano for example, that's where CueMix would help.

The difference between mixdown and live tracking of VIs is the pregen function. If a MIDI track has been recorded (and is no longer record-enabled), DP can play it back early to render the VI, and therefore save on live CPU use. When you're tracking with a VI, the VI is running in real time. The audio buffer determines how long from live MIDI trigger to audio output. A lower buffer = quicker triggering at the expense of CPU load.

So if you are tracking with a VI you really have no choice but to run a lower buffer size. There's a pretty good chance that if you printed the other finished VI tracks, you'd be able to lower the buffer size to track the single live VI at that point. An easy way to test this is disable (ENA button in tracks window) the playback VIs, lower the buffer, and see if you can track without glitches.

And... It's been my experience that visual spikes in the CPU meter don't always mean disaster. There's also a preference to disable the CPU Overload warning message. If you ignore the visual spike and disable the warning message, is the triggered audio clean? If so, rock on!

Dave

[chlorinedream]

If the 1024 buffer causes too much latency, anything else I can try to avoid spikes at 512 other than getting a new machine?

It seems really counterintuitive that playing the synth live (not triggering it via a MIDI track) while the transport is playing the song doesn't result in spikes - but playing the same synth live without the song playing does.

[mikehalloran]

A number of users here, the Facebook page and on MacRumors have decided that their current iMacs are no longer up to Omnisphere In the latest Mac OS. It’s not specific to Digital Performer.

[davang55]

If you are tracking a VI Cuemix is of no help. CueMix is useful for monitoring a live external signal directly. If you were tracking a real piano for example, that's where CueMix would help.

The difference between mixdown and live tracking of VIs is the pregen function. If a MIDI track has been recorded (and is no longer record-enabled), DP can play it back early to render the VI, and therefore save on live CPU use. When you're tracking with a VI, the VI is running in real time. The audio buffer determines how long from live MIDI trigger to audio output. A lower buffer = quicker triggering at the expense of CPU load.

So if you are tracking with a VI you really have no choice but to run a lower buffer size. There's a pretty good chance that if you printed the other finished VI tracks, you'd be able to lower the buffer size to track the single live VI at that point. An easy way to test this is disable (ENA button in tracks window) the playback VIs, lower the buffer, and see if you can track without glitches.

And... It's been my experience that visual spikes in the CPU meter don't always mean disaster. There's also a preference to disable the CPU Overload warning message. If you ignore the visual spike and disable the warning message, is the triggered audio clean? If so, rock on!

Dave
magicd

Posts: 1417
Joined: Sun Oct 31, 2004 11:01 pm
Primary DAW OS: Unspecified

Yes I see what you're saying. I'm usually tracking guitar live (I'm revamping all our old material from MIDI to mp3 so the sequences are already done) but I use the channel inserts in DP for my FX patch (Helix native). So with cuemix ( I have a presonus though but it has mixer function) I could route a direct signal out to my hardware Helix as well as the "dry" guitar to the audio channel. I could then monitor the output of the Helix so I get "my sound" in the monitor mix. Then I could tweak it later (or I could "print" the effected sound to a stereo pair also.) I WAS getting clicks and pops in the audio track playback.

I almost never record anyone else but me, it's just an expensive hobby but I also produce tracks for our band (we are aging former bandmates in it for one last hack before the nursing home).

Thanks for the tips, I'm going to try all of them tonight when I get home from work. I think I'm gonna have to spend some money though. I'll come back with th results.

[HCMarkus]

One quick and dirty way to record new VI tracks when there is a lot going in a piece is to use a hardware synth monitored via hardwire to perform the part, then play back thru the VI. If you use a hardware sound that is in the same ballpark (attack/release/velocity response) as the VI sound, you will perform the part appropriately.

Alternately, do a quick mix of the piece, disable all but the mix and desired VI track, reduce buffer (better now in DP10.1 where sample re-load is not triggered) and perform/record with your desired VI. Then raise buffer, re-enable the tracks, and continue.

[davang55]

WELLLLLLLLLLL.......... ( I feel real dumb now)

The buffer was set to 64...... I raised it to 128..No noticeable latency. no more RED bar!!!

JUST FYI here's all the tracks and VIs:
Komplete Control-synth patch
ARIA player from GArritan JBB rhodes
Kontact-Hybrid Keys rhodes layer
Kontact-Session strings
Kontact-F Horn
Kontact-Bell patch
Kontact-3 PADS
Kontact -PERC track
Rhy gTR audio
Solo gtr audio
GTR montrack w/Helix Plug in
Kontact Dr KIt
MOTU Bassline VI

so that's 10 VIs 3 audio tracks, an AUX track for reverb and the master fader with an EQ plug in.
Not bad i don't think, .2

and no tricks used to save the processor. Case closed.

Thanks for all the suggestions and Help.

BTW I didn't mean to co-opt the OP on this topic.

[davang55]

Happy New Year, new gear, new probs!

OKAY so I got a used MOTU ultra lite mk3 and installed CueMix FX (my previous interface was a persons 1810). Besides cuemix signal routing being very confusing to decipher, the Computer audio is being sent to Analog outs 1/2 (which are not controlled my the master level control). I have been through all the setup screens and have assigned it to "LR MAIN" but I only get audio from the MAIN when I run DP with cue mix OFF. Then the master channel is in control, with cumin on it is very frustrating.

I'm sure I'm missing something!

Jeff

[davang55]

I found a workaround:
since the computer audio is going analog out 1 and 2 I assigned that to the "MAIN OUT ASSIG' in MOTU Audio Setup BUT you must click the "MONITOR" button in CueMIX for that output channel or you get the FULL output level and the level control on the Ultralite is disabled for some reason. This was all MUCH easier on my Presonus 1810!