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Arksun · Post by **Arksun** » Fri Jun 30, 2006 1:10 pm

I think there's some real issues with CPU usage with the latest version of Sytrus.

When playing notes on the keyboard, the CPU just spikes right into the red for first second holding up the audio, before settling back down to the held note cpu rate. Even if this average cpu load is quite low makes no difference. It's like the Sytrus is demanding a huge amount of cpu on the initial key strike.

This is from upgrading from 2.0.6 to 2.1. In 2.1 my presets spike like crazy and are unplayable, uninstalling and going back to 2.0.6, same presets play perfectly fine. No spikes.

This is with P4 3.2 , 1gig RAM. Cubase SX

Something you guys might want to look into. Going to stick with 2.0.6 for now

Arksun

Cosmic Bandito · Post by **Cosmic Bandito** » Fri Jun 30, 2006 2:02 pm

I have sort of had this problem with Sytrus as well. Usually it depends on the patch. Just as you decribed, it's on the initial strike, the meter in ableton live will only be at 30% but it will crackle.

I can usually work around it by freezing the Sytrus track in Live early on. That seems to work for me. The sound Sytrus makes are sooo huge though, and if your playing in realtime something has to give, so I'll live with it.

reflex · Post by **reflex** » Fri Jun 30, 2006 2:07 pm

Arksun wrote:This is from upgrading from 2.0.6 to 2.1. In 2.1 my presets spike like crazy and are unplayable, uninstalling and going back to 2.0.6, same presets play perfectly fine. No spikes.

What preset(s) does this happen with?

Arksun · Post by **Arksun** » Fri Jun 30, 2006 2:17 pm

reflex wrote:
Arksun wrote:This is from upgrading from 2.0.6 to 2.1. In 2.1 my presets spike like crazy and are unplayable, uninstalling and going back to 2.0.6, same presets play perfectly fine. No spikes.
What preset(s) does this happen with?

All of em (apart from mono/ mono arps), every single one, and my own too.

Ok this is a bit more interesting, I just re-installed the 2.1 again to investigate further.

It only seems to happen if more than 3 notes are played on my keyboard (or 1-3 notes played, than another which crosses over envelope release) then the spike hits.

Playing one or two notes (or mono) fine, but 4 or more it just doesn't like it.

Given this happens on all presets, regardless of cpu hit, this very much seems to be a 2.1 issue. Like I say 2.0.6 no problems (never tried the 2.0.7 or other revisions of 2.0 so can't comment on those)

Arksun

reflex · Post by **reflex** » Fri Jun 30, 2006 2:24 pm

Does it happen when you use Sytrus VSTi in FL?

reflex · Post by **reflex** » Fri Jun 30, 2006 2:32 pm

I think "Half volume" doesn't work anymore. Unfortunately I don't think I can post a fix right away.

Arksun · Post by **Arksun** » Fri Jun 30, 2006 4:05 pm

In fruity producer edition 6.0.8 it seems ok, but even there I've noticed the cpu kinda jump up to high values. Whilst I don't get the spike issues it's hard to tell if that's affecting the fruity version too. But the VST version of sytrus, very much a problem.

Will stick to 2.0.6 for now then until new fix comes along.

Arksun

smart · Post by **smart** » Fri Jun 30, 2006 4:14 pm

I've gotten a lot of spikes with Sytrus as well..

tony tony chopper · Post by **tony tony chopper** » Sat Jul 01, 2006 9:55 pm

It's like the Sytrus is demanding a huge amount of cpu on the initial key strike.

It's the case, and it's not a bug, it's related to the 'bandlimit' oscillator option. Will be a little improved in a future release, however it will always have an impact at the time the voice is triggered.
It's can only be a problem if you've set a very short (<10ms) soundcard latency, though.

Arksun · Post by **Arksun** » Sun Jul 02, 2006 11:42 am

tony tony chopper wrote:
It's like the Sytrus is demanding a huge amount of cpu on the initial key strike.
It's the case, and it's not a bug, it's related to the 'bandlimit' oscillator option. Will be a little improved in a future release, however it will always have an impact at the time the voice is triggered.
It's can only be a problem if you've set a very short (<10ms) soundcard latency, though.

How can it not be a bug if, with the previous version I can actually play my presets, but with this new 2.1 version ALL the presets are now unplayable. Is that whats called a feature? lol

This renders the Sytrus VST version unusable for me and if its not fixed then it will mean the same for many other users of Sytrus.

You can't use a synth that causes the CPU to jump right into the red initially, even though after that point it may only be using 10% total power. Expecially when lots of other sounds are loaded into the project!.

I'm sorry but I find it very strange you're defending this when the whole point of playing soft-synths is to have a latency of 10ms or less!.

My latency is exactly 10ms. Everything worked before, now sounds are unplayable. So what exactly is the advantage of this 'bandlimit' option and how do I turn it off in 2.1?

Like I say, when the preset isn't a mono one, this affects ALL of them

Arksun

tony tony chopper · Post by **tony tony chopper** » Sun Jul 02, 2006 11:51 am

How can it not be a bug if, with the previous version I can actually play my presets

but previous versions (depends how old) didn't have the bandlimit option. If you're saying that a previous version with bandlimited option was faster, it's not normal.

So what exactly is the advantage of this 'bandlimit' option and how do I turn it off in 2.1?

it's for common subtractive synthesis, to bandlimit oscillators without oversampling the whole stuff. It's in the operator tabs. If you're already oversampling a lot, no need for it. But oversampling wastes a lot more CPU than just bandlimiting oscillators.

My latency is exactly 10ms. Everything worked before, now sounds are unplayable.

You mean you can't even play 1 voice? It's not normal. It should only start to matter if you're coming close to 80% CPU usage.
But you should try the FL version, because if the VSTi works differently for you, then there's a bug and Fred can fix it. But it's easier for us if you try the FL version, that removes the big unknown that's the host.

And what's the filedate of your previous version? Note that Fred will be on vacation for some weeks.

Arksun · Post by **Arksun** » Sun Jul 02, 2006 12:13 pm

If you read everything thats gone before in the thread tony you will see that a bug was indeed acknowledged and he said he'd try to fix it in a new update. I made the mistake thinking you were worked for them by the way you seemed to be very specific to a new design implementation, hence my reaction.

It feels like you're only half reading the posts on this thread, I wrote twice about it doesn't affect mono sounds, and that its quite specific to when 4 or more notes are played.

2.0.6 works fine, all presets (factory plus my own), can't speak for 2.0.7, I jumped straight to 2.1, all poly presets affected with spike, factory + my own, regardless of their preset settings.

Helps when reading everything written in a thread sometimes eh

Arksun

tony tony chopper · Post by **tony tony chopper** » Sun Jul 02, 2006 12:20 pm

you will see that a bug was indeed acknowledged and he said he'd try to fix it in a new update

not really, fred was only talking about the broken 'half level' option

I made the mistake thinking you were worked for them by the way you seemed to be very specific to a new design implementation, hence my reaction.

but I made it, I'm gol. It's just that it's the VSTi version, and fred is in charge of porting it.
So the original is a fruity plugin, and if you can tell if if it's the same problem in FL, then it's a problem on my side and I can fix it. Otherwise you'll have to see with fred if it's something in the VSTi.

But again, there should be a little CPU bump when you trigger voices, but nothing that could hog the CPU for just a couple of voices, even a dozen of them. The effect shows more in a full song.

specific to when 4 or more notes are played.

that doesn't sound like enough voices. Unless your patch uses 6 operators all in bandlimited mode (which you can switch off), but even there it's not enough.

You should first try to switch the bandlimit off for each operator, so that we know if it's the cause, and then give a try to the FL version.

tony tony chopper · Post by **tony tony chopper** » Sun Jul 02, 2006 12:22 pm

and in all cases, plz attach one of the offending patches so I can try

Arksun · Post by **Arksun** » Sun Jul 02, 2006 12:33 pm

Hi Gol,

Ok, I don't think its a Band Limit issue.

I loaded up 2.0.6 in cubase.

Playing first factor preset SynStr-Rich ensemble, 5 notes at same time (a bass octave and a chord), like you would playing a pad sound.

B.Limit is switched on.
Initial key strike, cpu meter in cubase (which I realise isn't strictly a true cpu meter at all) jumps up to 18%, then settles back down to around 9%.

But all in all plays just fine, no spikes at all.

Turning B.Limit off on the oscillators, no cpu jump on initial strike, goes straight to 9% and holds there.

Now doing exactly the same with 2.1

B.Limit is switched on.

Initial key strike, silence, cpu overload red light comes on for half a second. Then the cpu level jumps back down to 9%

B.Limit is switched off.

SAME

It's not a B.limit issue, must be something else. I made sure the 'B Limit' was unchecked on all 6 operators (even though that preset uses only 3) but no joy. :/

Arksun

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CPU Spiking issues with Sytrus 2.1