@Juicy-Jr Some additional thoughts:

• In case you thought otherwise, [block~ 1 1 1] does not oversample, it just makes the block size 1.
• You could apply the smaller block size to a subpatch or abstraction and isolate the feedback portion inside it. That way you only pay the CPU price for the stuff that needs it.
• MIDI 120 = ~8372 hz, and 44100/8372 = ~5, so [block~ 4 1 1] would suffice and be a bit cheaper. [block~ 8 1 1] would get you to MIDI 112.
• I know I'm in the minority, but I feel that my CPU works for me, not the other way around, so if something is computationally expensive, I don't worry about it until my machine can't keep up. Pd's load meter seems to exaggerate in Win10 because I routinely run at loads >100%. Finally, you can use [pd~] to distribute computation among several cores if necessary.

@Juicy-Jr Caveat: if you have feedback, then that ordering technique won't be possible. In that case, I think your best option would be to reduce the block size, e.g. [block~ 1 1 1].

@Juicy-Jr Are you making sure that delwrite~ is executed before delread4~? If not, I'm guessing that at sample rate 44100 and block size 64 your frequency can't go above 689 (44100/64). If I'm right, take a look at Pd vanilla help 3.audio.examples/G05.execution.order.pd.

@whale-av I'm guessing that when @KoaN writes about MIDI latency, what they are measuring is interval between when a MIDI note message is sent and the onset of sound from the plugin. That's why I'm curious about those audio settings, which I didn't see mentioned among their replies.

@KoaN In the File->Preferences->Edit Preferences... pop up, on the Audio tab, what have you selected for Delay (msec) and Block size?

@waffles If the patch is still popping because it's missing real time audio deadlines, try staggering the bangs from [metro 50] by substituting different length delays (e.g. 2, 4, 6, 8...) for the [bang] objects. That will distribute the control rate processing more evenly. Another thing to try is to delete any UI element you don't need. The patch stopped locking up my machine once I removed the vertical sliders near the AR oscillators. Finally, I noticed that sometimes it triggers a chime a couple of 50 ms intervals in a row, which is kind of a waste, so I added a 1 second lockout to ARosc~ to enforce a minimum interval between triggers. You can change the lockout time by changing the delay. ARosc~.pd

@waffles On Windows 10/Pd 0.55.2, this patch somehow prevents me from switching between windows or accessing the taskbar, except when task manager is open. I'm guessing it's related to the fact that all the bangs hanging off of the [sel 0]s are solidly on, suggesting that the patch is falling behind in the control domain and perhaps missing realtime audio deadlines in the audio processing. That would definitely cause clicks.

I also notice that the connections coming from each of those same bangs are not explicitly sequenced with a trigger object. I'm assuming the author intended [line] to jump to 1 first, which could also be a source of noise due to the discontinuity. Even if you took @seb-harmonik.ar's suggestion to replace it with [line~], that discontinuity would still be there.

If I could somehow get this patch to let me edit it, my first experiment would be to cut out most of the repetition to see how various subsets behave. I think that would give me a lot of information about why the patch is making so much noise.

Edit: just learned about the -noloadbang flag. <other silly BS deleted >

Another edit: Let me know if this works better for you--this version doesn't freeze my computer. calm-generative 4.zip I replaced the loadbang with a toggle so it wouldn't start immediately. I added abstractions for each LFO and each AR oscillator to help me see what was going on. The latter lengthens the attack to 20 ms (from 0) and also controls the final volume using the LFO signal itself, rather than the one sampled every 50 ms, in case that was the cause of the zipper noise you were hearing. I deleted the oscillators that weren't connected to the dac in case they were eating CPU. It should be easy to add them back in now that you have the abstractions. I combined all the metros into one in case it helps reduce the control rate processing, and in an earlier version I staggered the bangs by 2 ms, but that didn't seem to make a difference. Finally, I noticed some light, occasional clipping, mostly in the left channel, so I halved the signal.

FYI, an algorithm I was taught in school uses a heap-based priority queue for that B array. Makes it a bit faster in big-Oh terms.

@freq63 If you want to follow my suggestion, the issue is here in your Arduino code:

As @FFW was explaining, you are putting a single value on each line, but your Pd patch is looking for 4 values on one line. Try this instead:

for (int i = 0; i < 4; i++) {
  Serial.print(myArray[i]);
  Serial.print(" ");
}
Serial.println();

Serial.println() comes after the loop where it only outputs a line terminator once for all 4 values.

@freq63 +1 to @FFW, but your patch as is suggests you are sending the data incorrectly. On the Arduino side, try printing 4 floats on a single line separated by spaces, then terminate the line with /n (i.e. use Serial.println to terminate the line). You can see an example for 2 floats here: https://forum.pdpatchrepo.info/topic/13086/arduino-to-pd-vanilla/8