Sometmes I am so goddamn tired of renoise
Now it’s 50% cpu in taskmanager by just bringing up the gui pof Tranzstow , zebra 3 is also heavy on the graphics
By just moving a goddmamn slider with my wacom pen the cpu shoots 50 %
How come renoise is the only host that exhibits these issues ?
Using the exact same plugins in other host this issue never occurs , it’s tiresome
Since this process (plugin instance) runs within a single track, Renoise logically assigns it one processor core.
Core #1: It’s 100% used because it has to calculate all 8 Tranzistow parts, all its modulations, effects and filters in real time.
Cores #2 to #16: They’re basically bored or doing other small jobs.
As soon as Tranzistow on that one core fails to calculate the sound in time (before the audio buffer runs out), you will hear a crackling sound or Renoise will start reporting “CPU spikes”. The overall performance of your PC is unused, because one core acts as a bottleneck.
When you create an Alias of an instrument in Renoise (to send MIDI data to the same Tranzistow instance from another track), Renoise still has to send all the audio processing of the original instance to the same core.
Furthermore, Tranzistow is extremely demanding on processor instructions (it is not exactly “economical” code, it is pure power), which increases the pressure on one core even more.
How to get out of this? (Possible solutions)
If you want to use Tranzistow more efficiently in Renoise, you basically have two options:
Multiple instances instead of one (Recommended):
Instead of using 8 parts in one Tranzistow instance, open 8 separate Tranzistow instances (one in each track). This will force Renoise to send each instance to a different processor core. The overall load will be nicely distributed.
Note: Tranzistow is “multi”, but modern DAW workflows today tend to follow the principle of “one track = one instrument”.
Increasing the Audio Buffer:
If you insist on one multitimbral instance, you need to increase the buffer in the sound card settings (ASIO) (e.g. to 512 or 1024 samples). This will give the processor more time to calculate, but will increase latency (delay when playing the keyboard).
Disabling some modulations:
Tranzistow has options in the settings to relieve the CPU (e.g. reducing oversampling or filter quality), but that’s a shame for such a synth.
Verdict: Renoise is great at parallelization, but only if you give it a chance by “chopping” the instruments into multiple tracks as separate instances. Multitimbrality in one VST is already a bit of a legacy of the hardware sampler era in 2026, which modern processors paradoxically resist.
Tranzistow gui will definitely not be CPU intensive, you have to know that yourself 
I would look for a bug in the drivers for the pen. Monitoring events is demanding, especially for pointing devices.
I only use Tranzistow in the HrastowX2 environment because that’s where you can use it to its full potential. This screen is from Linux where the private version of X2 is still running under Wine and I haven’t gotten over 10% CPU yet.
But it has one weakness. Because of this midi implementation I can only use one instrument (TW1). Although the private version allows me to use 4 threads, as soon as I want to use some notes (by setting the filter) I have to use TW2, unfortunately. In Linux under wine this will overwhelm Renoise and all the others because of “Wine” :(. Tranzistow is the only thing that still makes me dualboot on Windows.
I’m more bothered by the insufficient midi implementation in Wine 
