Hey, I’m dying here with my P4 2.4Ghz CPU going 80% with 9 VSTIs loaded!!
WTF??
I don’t know where to post this so I posted here.
Is there anything I can do to lower the cpu level?
A couple of things you can do:
In the Instr. settings of each VST instrument
You can try to toggle the auto suspend checkbox to make Renoise suspend the Vsti when no output is being submitted by the Vsti. (Does not work with every Vsti)
In the Config Properties:
You can either raise the latency of your audio-card (the higher you set it, the more it will reduce your cpu usage) or;
If you need lower latencies, reducing the frequency-rate of the
sound-output may work as well or;
You can set the CPU Usage in the Audio tab to working or LowCPU to reduce cpu usage. Though this will disable usage of effect-output in a more or less way.
In the GUI tab, you can switch off a few fancy Gui effects, but this will not free that much cpu resources.
There are various options you can trigger to bring a workable balance in your audio-needs.
Also there are topics existing mentioning Renoise having problems with hyperthreading CPU mode, but up to now this was only for AMD processors.
Multithreading should be enabled / disabled in the System BIOS.
The way i get round it is to render all the CPU hungry arps and instruments into wav’s and use them as samples…
My songs begin to f*** up when the (AMD) cpu level is at 60%. At which point does your songs f***
its song dependant over here.
some tunes start to get choppy at around 55% - others at aprx. 65%, but beyond that, everything i’m able to run through renoise will become awkward (GUI + audio stutter).
i just hit the border again, with 2 instances of minimoog V, 1 instance of korg ms-20 and a tiny little instance of microtonic. peaks at around 67%, renoise becomes VERY unresponsive and audio/gui stutters.
seems like either renoise has some serious problems here, or the days of my p4 3.5Ghz are counted and i’m in the need of something more performant.
whatever… i really wonder why we can’t use renoise properly up to 99% CPU load… why? 
hmm the RAM i’m using is pretty adequate for my CPU i guess.
it’s PC4000 DDR running at 250mhz (500mhz DDR) at low latencies.
think i’ll rewrite the tune in cubase for the sake of clarity towards this concern.
I’ve raised the somewhat same question… it appears to me that renoise does not calculate the VSTi’s cpu use correct.
Besides CPU utilisation you have memory and diskutilisation, but those stats are not being measured.
If you have VSTi’s that does a lot of disk utilisation (playing samples from disk) but your harddrive isn’t capable of handling the speed, cpu usage may be even 20%, your sound still will stutter.
Even if every VSTI is set to handle samples from memory:Once your memory is full, your paging-file is then being used thus:still playing samples from disk in some cases.
It’s not only cpu power that determines if your sound-output will be steady.
both scenarios you describe there vvoois, are pretty exceptional and prescind from the actual problem where neither the harddrive nor the memory is the limiting factor.
i’m talking about songs that rely on realtime synthesis to output sound and do therefore not occupy 1GB of memory for flawless operation.
besides that the kernel’s performance meters are always monitored by samurize here, so i always know how much of my physical memory is being used at a specific point of time and how much traffic my striped array has to manage.
don’t come to renoise’s defense, when there’s no reason to do so 
my conclusion is that either renoise’s CPU meter is understating the actual load of the processor or there are still free CPU resources when audio output becomes flawed at around 65%, but renoise fails to make use of these for some reason.
i assume it’s not the latter case.
Well, it’s only supposed to measure Renoise’ audio consumption. Though I don’t trust that meter cause the test song has proved that it also takes gfx into consideration to some amount.
whatever it measures, imo it should give the user an information about how much CPU resources he has left until the song becomes to heavy to be calculated in realtime by his system.
so in general i expect everything to go well until my CPU goes all the way up to 100% load.
I agree, what else could matter?
Anyway, i just tried korg legacy cell, and when jamming i got the cpu measurement counter up on 30% in VST instrument properties, but the overall (top right corner) were saying a stable 12.9%. Something is not right.
I’m sorry… but i’m still the man of samples actually so that’s the basic point i start my first thinking. I don’t use much synth-vsti’s either, i rather scramble the samples and waveshape them to something different than using a synth engine.
Everyone’s different choice for instruments i guess.
sampling synths or bouncing sequences is great… but really hinders your possibilities.
samples lose dynamics when layered across multiple octaves and you also lose lfo, filter, etc modulation control.
therefore all my songs are meanwhile almost 100% VSTi only.
just a few percs + fx are sample based.
so to sum this all up, i guess we do all agree that a more accurate CPU meter would really be a neat thing to have.
there are some VSTi (especially on high polyphonic use) that produces more than 10% cpu-usage per instance on my 3 ghz @ 3.4 P4 … normal thing in my opinion …
maybe the reason for differences of the cpu & vst-cpu usage display are that the vsti-cpu-usage shows the usage produced by the VSTi only. the usage of Renoise (audio-engine, pattern-movement and so on) is excluded in the vsti-cpu-usage display.
Why are there 3 threads discussing this problem…? 
don’t know … i have no problems 