Problems with load balancing


hope everybody still in christmas mood and relaxing. Nevertheless I have an issue with load balancing on my i7. I got serum from xfer and have to say it really is “eating” the performance of my 4 physical cores. However I was able to handle one instance of serum with one core.

Strange things happened when I tried to drive more than one instance of serum in parallel: even with only 2 instances I got dramatical overloads and massive dropouts.

A look on ressource monitor showed that cantabile obviously tried to handle both instances by the same core even though the cpu settings were set to automated (4 cores).

I changed this to fixed 4 cores and so was able to handle 4 instances with acceptable load balancing now.

This was still true even after going back to “automated”!

I saved the song, restarted cantabile, called it up again and now everything was fine from beginnig.

To be sure it was no single event I tried to reproduce the whole procedure which was possible.

So my question: did anybody of you have similar observations or a hint what could go wrong here?

Kind regards, humphrey

Edit: meanwhile I checked what happens if I start the whole thing with number if cores fixed to 4. The behaviour is exactly the same and balancing now works if I change the setting to automated - strange. It also doesn’t seem to depend on serum as I also got the problem when adding 1 instance of DIVA to 1 instance if serum. A test with 4 DIVAs didn’t show the effect. Btw: I used agressive mode all the time.


additionally I did the same tests in Ableton Live 9 and Cubase 8.5: both were able to handle load balancing without problems concerning serum.

Regards, humphrey

Edit: meanwhile I was able to recreate the issue with 4 DIVAs in devine mode (so NO serum plug inside). Seems to be be not bound to serum but to high cpu loaded vstis.

Another aspect: if I store a song where I could fix the issue by changing the multicore settings cantabile seems to remember this (so far).

humphrey, you did much more than I ever knew of doing. However, I tried incidences of Sylenth, Hybrid 3, Retrologue 2, Massive, Waves Codec and Waves Element to check the cpu load. I noticed that all synths except the waves synths generated lush thick sounds throughout the register with a surprisingly low impact on the CPU. I am running an i7 with 16gb ram. Waves synths were shockingly thin and the lower register when playing pads decimated my cpu load. Tried everything to fix it. No go. Opened Cubase Pro 8.5, same load from waves synths. I now have to weigh the value of the sound of the synth versus cpu load. Sonnovox and Waves have no use for me at this point.

My opinion, as a programmer myself, the same thing can be accomplished with either efficient, lean code or lengthy code. Seems to have a major impact on resources. Again, that’s my opinion.

Thanks for the post. I have always been afraid to use aggressive.

Hi John,

thanks for replying and sharing your experience. I`m not absolutely sure if I got everything but here some of my thoughts:

First off: my problem is not that a special plugin is using much cpu power. This also was the case with DIVA when I bought it and so it would be my personal problem if my cpu can`t stand the load. But here I have the problem that a single instance of a vsti (and together with DIVA I see 2 now) can be handled by one core of the cpu without problems. The problems occour if I use more than one instance as cantabile seems to be not able to use the 4 physical cores of my cpu.

What`s annoying: this is only true as long as I change the multiprocessor-settings in cantabile by hand. After this (even if I turn back to the original settings) cantabile does this load balancing properly! So it obviously is able to do it).

Checking with other DAWs shows me: they are pretty able to handle this. So I see it as a potential weakness in cantabile (besides my personal problem here).

Concerning different VSTis: I agree Serum is a special type of vsti. Steve Duda (the programmer) told some of the ideas and intention behind and I found them very straigt foreward. Serum is a plug with little compromise concerning sound quality (specially items like frequency range, artefacts, aliasing,…) resulting in increased cpu load. What convinced me was the fact that everything I did with this little monster sounded great without knowing why (this was before digging deeper into the background story).

I have some of the typical candidates for lush, thick sounds here: the good old Silenth 1, HIVE, and as representatives of Wavetabels Massive and the Waldorf Micorwave 2. I also had an ear on the Waves Codec. For the last I totally agree: totally thin, sounds like a quick shot to be in the lotary.

Massive is good one but not my no 1 for thick sounds (Multi Saw Tooth and the like).

Sylenth 1 was a good synth when it was released and I now it has high reputation in the field of dancefloor etc. (there are tons of soundlibraries available). But compared to HIVE it has this plasticistic touch.

So I tried some testing: There is a simple but very thick sound in Serum (no wavetable) I tried to recreate in HIVE and Sylenth 1: whereas HIVE got me pretty near Sylenth 1 totally failed for me. There was always this cheap aliasing in the background I don`t like (and I totally agree: all this is a question of personal taste here!!).

HIVE did a good job but in Serum everything sounded more transparent (which of course will not always be what one is whishing).

There are some more aspects that drove my to purchase Serum:

  1. It comes damned near to the sounds I know from Access Virus
  2. For me front end and resulting workflow are awsome (and again: personal taste!). It was the first synth since years that let me do sound programming for days (this is not typical for me). I get everything I need with a few clicks.

So I decided to purchase it and Im happy with it like on first day. So you probably can imagine why Id be happy to have this little machine running properly in cantabile.

All this not meant to be agressive and far from trying to convince anyone from bying something (and no: I`m definitely not on the payroll of xfer records ;-)) - only my personal view on things.

Kind regards, humphrey

Access Virus is beyond the best. Now you have me thinking about that synth. Interesting we are having this conversation. I am about ready to take the plunge with Omnisphere 2. Lots of different programming environments. Seems like you get a lot for the money, and I really like the electronic band Nero, which was my first exposure to the sound. Any opinions on Omni?

Indeed the partials in NI Razor kills the cpu but the sounds stand out in the mix.

Tried an alternate to Cantabile, but the CPU load report did not seem an accurate representation. Made me feel I was safe indicating low CPU usage, when that was not the case. I.e dropouts with seemingly low cpu usage. I feel that Cantibile is at least giving an accurate representation.

Thanks for your reply. Looking forward to your opinion.

Ah, Omni! Yep, purchased it when Omni 1 was released and still one of my favorites. I also have Trilian and Stylus here using them very often. Even for the price: a no-brainer!

So you may ask: why no Omni 2? Well, thought about it but then: there is not so much enhenvement in sample content. Instead (interesting) new sound manipulation including sample import (so far one could even see it as a wavetableoption).

When I compared with Serum: well at least it’s these special sounds I didn’t get out of Omni and I don’t expect to get out of Omni 2 - and I’m possibly wrong here!). So my decision was to buy Serum over Omni 2.

But: If I didn’t have Omni 1 I’d most likely vote for Omni 2…

NI Razor: I confess: it’s somewhere on my ssds but never used it till now. So sorry: no usefull impressions from my side.

Concerning Cantabile: I use c2 for years and can say: really good piece of software, reliable and beloved. Disadvantage: even though no bigger bugs inside development stopped for years!

When Brad announced a complete new core for c3 I first didn’t believe it. But what he has done during the last year is far more than I’d have thought of in my wildest dreams!! I also support the way of paying for 1 year support and updates. If Brad is available and cares for the users needs this is absolutely fair!

So you can see: I’m a strong bekiever in cantabile 3, for me it will be the best live host available for keyboard players (and more ;-)).

But this doesn’t hold me back from pointing to problems I see and I think could not only be a problem for me (and to be serious: if anything stability is THE aspect that keeps most keyboard players from using computers on stage).

If anything I’m a bit afraid of a cantabile 3 for the super professional tricky users with thousands of whistles and bells and loosing the (big number) of “normal” users not knowing how to get this rocket started.

Btw: I’m also a longtime user of forte and there is nothing cantabile is to blame for (besides: also forte has problems to handle serum although in another way).

Kind regards, humphrey

Now you’ve had me looking very closely at Serum for several days now! :smile:

It seems thoroughly amazing, but I do worry about whether my CPU can hold up to it. I already struggle using LinPlug’s Spectral which is another number-crunching mammoth of a synth.

Everything I’ve heard from Serum sounds terrific!


Been out of contact for a while. BUSY! Trying to work full time and complete a Masters Degree. Not advisable. Thanks for the input on O2. I was playing a rather large gig (couple thousand, that’s large for me) and I had a note stick while doing a sweep with VB3 (this is the only problem I have had for the over three years I have been using Cantibile). I have an i7 16gb RAM and a 240gb SSD. By the time we were done with that verse, I was rebooted and alive to make the chorus. No one noticed (except for the random stuck note and temporary drop out)… I have a trusty Motif Classic 7 as my backup on stage just in case. I have to say Serum looks like a GREAT vst. For 189 seems like a good deal. I just wonder if it is hard on the CPU.

Undoubtedly, Serum is my next purchase. WOW! I needed some specific functions, and this covers them all. So much can be done within the program, without the fluff of O2 (except I was impressed with O2 granular synth for pads). Astonishingly clean! I love that!

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yep, it’s really the cleanest vst of this kind. The wavetable editor is a show of it’s own and I also like the graphical interfaces.

I confess: sometimes sound differences to similar plugins may be subtile but if you like these aliasing free sounds there is nothing competitive out there.

On the other hand you’ll be paying with big cpu load. For one instance this is not a problem here. Smilar to your setup I use i7 cores (4770k for desktop and 4702qm for lappy) with 16Gbytes of RAM and SSDS. The problem occours beginning with 2 instances reaching +100% sometimes.

When changing to a different cpu setting in cantabile and back to auto I can fix this reaching about 50-60% max. even when using 4(!) instances of serum. As serum has become one of my favourites cantabile is not usable for me as is atm.

If you’re able to reduce the number of serum instances to 1 you should be fine.

Regards, humphrey

Live I would probably use only 1 instance of Serum and try to automate patch changes (kind of a drag live) and using MIDI triggering to enable/disable synths to redeem the cpu. I use an MPK261 and that thing is an absolute MIDI beast. I don’t like to switch songs, presets etc much during a show. I just have a massive list of plugins in Cantabile routed to a Waves L1 Ultramaximizer for final output when I play live, and enable synths I am using for that set. (only problem is the initial load time is pretty long). I have The Grand 3, FM8, VB3, Hybrid 3 (for leads mainly), Padshop, NI Classic Keys, Halion 5 (good for sample triggers BUT i noticed that Serum does those triggers in the Noise section), and GrooveAgent 4, routed through L1. Yes, I am a Steinberg fan. Getting into Ableton, however.

Thanks for the switching CPU settings trick. CPU overload is a deal killer for me. Hybrid 3 has been my lowest CPU load, highest versatility for performing. Serum may be a backing track workhorse (possibly). Nevertheless, it’s on the list before O2 for me.